Whatever the Council decided to do about what is a hugely sensitive and polarising topic was always going to provoke unhappiness in one quarter or another.

The surprise felt by many who had been advocating for athletics to follow the lead already set by World Rugby and World Aquatics in barring trans athletes from female competition was explained by the fact that World Athletics policy seemed to have shifted back to a previous iteration.

Last summer, on the topic of trans athletes, World Athletics President Sebastian Coe had commented: "Biology trumps identity", adding: "If we ever get pushed into a corner to that point where we’re making a judgement about fairness or inclusion, I will always fall down on the side of fairness … fairness is non-negotiable."

But the clarity of that message - whether one liked it or not - was muddied with the news on January 21 of World Athletics’ "preferred option".

This involved allowing trans women - and, separately, athletes with naturally occuring differing sexual development (DSD) -  to compete in the female category, as long as they reduce their amount of blood testosterone from 5 nmol/L to below 2.5 nmol/L and stayed below this permitted threshold for two years, not one as before.

At the same time, World Athletics accepted that this would not level the playing field, given "the preferred option would allow significant (although not full) reduction in anaerobic, aerobic and body composition changes".

That said, a statement by a World Athletics spokesperson before the Council meeting hinted at a different direction in describing the preferred option as "the best way to gather constructive feedback, but this does not mean this is the option that will be presented to Council or indeed adopted.

"In terms of our female eligibility regulations, we will follow the science and the decade and more of the research we have in this area in order to protect the female category, maintain fairness in our competitions and remain as inclusive as possible."

When push came to shove last week Coe, who incidentally confirmed he would be running for a third term as World Athletics President, was back in summer mode as he announced: "We weren’t prepared to put women’s competition in jeopardy.

"It is a principled decision founded on the overarching need to protect women’s competition. That is what we needed to do, and that is what we have done I believe."

A World Athletics statement said: "The Council has agreed to exclude male-to-female transgender athletes who have been through male puberty from female World Rankings competition from 31 March 2023.

"World Athletics conducted a consultation period with various stakeholders in the first two months of this year, including Member Federations, the Global Athletics Coaches Academy and Athletes' Commission, the IOC (International Olympic Committee) as well as representative transgender and human rights groups.

"It became apparent that there was little support within the sport for the option that was first presented to stakeholders."

As Coe put it: "We entered into a consultation some months ago because we wanted to provoke debate.

"It was really important that we heard from all our stakeholders, including the athletes, the coaches and member federations. And my goodness, we heard from them.

"The majority of those consulted stated that transgender athletes should not be competing in women's competition ... they believe there is insufficient evidence that trans women do not retain advantages over biological women."

That position has been greeted with approbation and relief by those who have been campaigning for such a decision for many months, such as Britain’s Olympic swimmer Sharron Davies, double Olympic marathon runner Mara Yamauchi, Ireland’s former world 5,000 metres champion Sonia O’Sullivan.

Davies won Olympic silver at Moscow 1980 behind Petra Scheider, who was subsequently shown to be a part of East Germany’s organised doping regime. She said she was "surprised but so pleased" at the World Athletics decision, adding: "I always hoped that Seb [Coe] would put fairness first and this is a really important step - and one other sports must now follow."

British long jumper Abigail Irozuru told BBC5live: "I think Lord Coe has done the right thing. It’s important for us to protect the integrity of female sport."

Her team-mate, 400m runner Emily Diamond, also hailed the decision, thanking those who had been "leading the fight for fairness in women’s sport," adding: "Today was a big day for athletics."

In another tweet, Diamond, an Olympic bronze medallist in the 4x400m at Rio 2016, said: "Hopefully this will be the rule across all levels now, not just elite ranking events."

Save Women’s Sport Australasia, a group campaigning against transgender athletes in women’s sport, also welcomed the move from World Athletics.

"It’s not a ban, it just actually moves to protect the female category to female competitors and it was an excellent decision,” spokeswoman Ro Edge told Reuters.

"So it’s really reassuring to hear World Athletics President Seb Coe come out and say they’ve got to maintain fairness of female participation above all other considerations."

UK Athletics, meanwhile said it was "fully considering the details of the World Athletics statement on transgender and DSD participation in athletics and its implications for competition in the UK," adding: "But in principle we support and welcome the direction they have taken in protecting the female category.

"This direction reflects the submission made by UKA to World Athletics earlier this year.

"At the same time, we remain committed to continuing to work alongside the Home Country Athletics Federations and our Transgender Project Group to maintain the inclusivity of our sport and ensure that transgender women are able to continue to compete whilst respecting these rules."

Others, however, viewed it as a bad day for athletics.

Liz Ward, director of programmes at Stonewall, which campaigns for LGBTQ+ (lesbian, gay, bisexual, transgender, queer and others) rights and equality, said: "It is so disappointing to see World Athletics announce a unilateral ban on trans women in track and field events.

"Their own statement recognises that there are no trans women competing at an international level and that they have no specific evidence to justify the ban.

"It is vital that decisions about trans participation are based on robust evidence, specific to the sport played and the athletes competing at that level of the sport.

"We stand with trans people who now have the door closed on their chance to compete in athletic sports at an international level."

Anna Brown, chief executive of Equality Australia, said in a statement: "Such policies risk violating international human rights principles of non-discrimination, which require such policies to start from a place of inclusion unless an exclusion can be justified as proportionate to any risks identified,

"World Athletics has failed to meet that standard."

Hudson Taylor, founder and executive director of Athlete Ally, a nonprofit LGBTQ athletic advocacy group based in the United States, said:  "We are beyond devastated to see World Athletics succumbing to political pressure instead of core principles of inclusion, fairness and non-discrimination for transgender athletes and athletes with intersex traits.

"The guidelines announced today go against inclusive guidelines from the International Olympic Committee as well as extensive research showing that transgender women do not have an inherent advantage in sport…”

In an Athletics Australia statement attributed to President Jan Swinhoe and chief executive Peter Bromley, the governing body said it "respects" World Athletics' decision to ban transgender women from competing in female world rankings competition while making it clear it was supportive of a more inclusive policy.

Athletics Australia acknowledged it was "required to abide by the rules set out by World Athletics for elite competition", but said it had "its own community-level guidelines for the participation of trans and gender-diverse athletes," adding: "These guidelines are underpinned by the principle of inclusion and are designed to ensure that athletics remains a sport that is welcoming and accessible to every Australian."

But Britain’s Amelia Strickler, a two-time national shot put champion who has also spoken out in favour of trans athletes having a separate category, was scathing of the Athletics Australia statement in an interview with Wide World of Sports.

"It seems like they're not happy with it ... and that they're going to do everything they can to keep it so inclusive that it sacrifices the women's game, which is unfortunate," Strickler said.

"I do think it's off the mark because they want to push inclusiveness. The (World Athletics) statement wasn't meant to exclude anyone; it just said, 'You have to compete in the category with which you are biological and we need to keep women's sport for women'.

“So, unfortunately it does seem to be misguided, because they seem to want to push inclusivity and World Athletics is not excluding anyone."

Coe insisted the decision had been made to “maintain fairness for female athletes above all other considerations.”

How to explain the shift back to the summer stance? South African Professor Ross Tucker, a science and research consultant for World Rugby who jointly runs The Real Science of Sport podcast, has speculated in the wake of the announcements.

“I think it's a significant moment in the history of this issue," he wrote, adding: “I'm fully supportive of this decision - it is absolutely the right choice to make, and they've explicitly said that the overarching principle is sporting fairness for women, which is 100 per cent correct.

"Once you recognise that, then you need evidence that you can achieve fairness with inclusion for trans women, and that evidence does not exist. In fact, the opposite does - all the studies suggest that male advantage persists well after testosterone is gone.

"So the correct action has been taken based on the biological reality and evidence.

“The IOC, meanwhile, are still selling the myth that you can balance TW inclusion with fairness/safety to women.

“They haven't yet recognised that inclusion means exclusion, that categories only work when they exclude people who should not be eligible, and they have propagated some amazingly bad science in support of that myth.

“I must confess that I'm surprised World Athletics went this way, though. At the start of the year, their preferred options was a reduction in testosterone below 2.5 nmol/L for 24 months. But that was widely rejected during consultation, particularly by women athletes who made their voice heard as part of that consultation.

“Plus, being the biggest of the Olympic family members, I imagine there would have been significant pressure to comply with the IOC's anti-biological policy.

“I've no doubt that it's the voice of those women that has swayed them. For all the science, it's women saying, 'No, we insist on integrity and our right to sporting fairness' that tilts the balance by making sport aware that this stakeholder group actually exist.

"So the brave athletes who risk vitriol and threats must take the credit. The IOC differ because they have actively sought to ignore and even silence the voice of women, choosing instead to hear what they wish to in support of biological denialism."

With athletics, historically the number one Olympic sport, now aligning itself with another of the major Games sports, swimming, there is likely to be growing pressure on other sports such as rowing and cycling which are currently operating in accordance with the IOC guidelines that sports should allow transgender women to compete in female events if their testosterone levels have been below 5nmol/litre for a year.

World Rugby, World Aquatics and now World Athletics are on a collision course with the IOC with less than 500 days to go to the Paris 2024 Games. Doubly so as far as World Athletics is concerned given Coe’s strong re-stating of the ban on Russian and Belarusian athletes from competition while the invasion of Ukraine continues.

That contrasts starkly with the recently expressed IOC wish to "explore" ways of allowing Russian and Belarusian athletes to compete as "neutrals".

Meanwhile, World Athletics may also have to defend its position in court - as it did when it attempted to curb the participation of DSD athletes and won a legal action against the the two-time Olympic 800m champion Caster Semenya which went to the Court of Arbitration for Sport.

Semenya is currently appealing to the European Court of Human Rights.

Asked on Thursday about the likelihood of a legal challenge, Coe responded: "It’s possible.

"If that is the case we will do what we have and vigorously defend our position.

"We will always do what we believe is in the best interests of our sport."

He explained that World Athletics would be setting up a working group to evaluate the issue of transgender inclusion over the next 12 months, adding: "We’re not saying no forever."

Asked if an open category was mooted, Coe said it had been discussed but added: "We think at this moment we have got the right approach."

Such a consideration may well form part of the working group’s future task.

As it stands, however, it is the decision taken over DSD athletes that will most dramatically alter the landscape of women’s events, given there are not currently any elite trans athletes on the scene as there have been in swimming, in the United States where Lia Thomas has proved a controversial figure in winning races by large margins, and cycling, in Britain where trans athlete Emily Bridges has run into similar concerns.

The DSD ruling now operates across all events rather than just the previous restricted range from 400 metres up to the mile.

Interim provisions will be put in place for DSD athletes already in competition outside the previously restricted distances and they will only be required to supress their testosterone levels for six months before competing in any World Athletics-sanctioned event.

But this still does not allow enough time for athletes such as Semenya or Namibia’s Tokyo 2020 200m silver medallist Christine Mboma to comply before August's World Championships in Budapest.

Meanwhile, there is a problem looming for World Masters events, and most pressingly for the World Masters Indoor Athletics Championships that are due to start today at Torun in Poland and are due to run until Saturday (April 1) - the day after the World Athletics ruling on trans athletes becomes operational.

The event is not under the jurisdiction of World Athletics but organisers have previously used the world governing body’s rules to explain the eligibility of trans athletes, including the Italian sprinter Valentina Petrillo, who is expected to challenge in the women’s 200m and 400m races for over-45s, the Daily Telegraph reported.

In a statement on the event website, the organisers said: "It has been brought to the attention of WMA (World Masters Athletics) that there have been some unacceptable comments placed online regarding the participation by transgender athletes,

"Any transgender athlete who has been accepted into the competition has followed and fulfilled the rules and regulations of World Athletics and has been screened and approved by World Athletics and is therefore eligible to compete.

"Any behaviour that involves intimidation, bullying, aggression or any other unacceptable actions, which would not be tolerated in any civilised society, will be dealt with appropriately."

Petrillo, who is visually impaired and also attempted to qualify for the Paralympics, began living as a woman in 2018 and started hormone therapy the following year. In an interview in 2021 with the BBC, she said: "I respect and comply with the IOC and World Athletics rules, I do the tests. I don't feel like I'm stealing anything from anyone."

World Athletics does not run World Masters events and has confirmed that WMA make their own decisions on adopting its rules and regulations.

But the WMA statement also contained the following: "Please can we remind all participants, as explained some weeks ago, that WMA is obligated to follow the rules and regulations as set out by World Athletics."

Insidethegames has contacted WMA to clarify its position given the new World Athletics ruling.

It appears possible that the WMA, if their relationship with World Athletics is as they maintain, will feel obliged to undergo a similar process with regard to trans athletes.

It remains to be seen how the ripples from Thursday’s decision may affect grass roots competition.