Doubts remain over whether the Seine will be fit for swimming during the Summer Olympics. The reigning Olympic open water champion, Brazilian Ana Marcela Cunha, is calling for a "Plan B" to protect the health of the athletes. Her request follows French president Emmanuel Macron's assurances on Thursday that there would be no problem. "Of course I will," Macron told reporters when asked if he would swim in the Seine, according to AFP.

The city has promised that the water will be clean enough to swim in by 2025. "I'm going to do it, but I won't tell you the date, otherwise you could all be there," Macron said. Organisers are still struggling to improve the water quality of the iconic French river, which will also host the triathlon events, five months before the long-distance swimming competitions on 8 and 9 August.

There were problems with last year's tests, when two bacterial indicators of faecal contamination were found to be above the permitted levels - in several cases, according to an analysis by the Paris City Hall. 

In an interview with AFP in Copacabana, Rio de Janeiro, Cunha, considered one of the best athletes in the history of her discipline, said: "Last year we didn't have the test event for this reason, and that's what worries us the most, because they insist on doing it there." 

"The history of Paris or the history of the Seine will not going to be erased (by not holding the race there). We know the value of the Alexandre III bridge, the Eiffel Tower. There are a number of important points for them, but the health of the athletes is the first priority," she added.

What is really worrying is the rain. The efforts to achieve acceptable conditions in the river water could be wiped out by heavy rain. Everything is in doubt, but the 32-year-old swimmer is determined to repeat the gold she won at Tokyo 2020. It will be her fourth Olympic Games and her seven World Championship gold medals (five in the 25km, two in the 5km) and 28 World Cup gold medals make her the favourite.

However, she will be up against world and Olympic champions such as Germany's Leonie Beck and the Netherlands' Sharon van Rouwendaal (gold in Rio). The Olympic organisers were officially handed the keys to the 52-hectare village north of Paris on the River Seine last Thursday. Paris has been working to clean up the Seine so that people can swim in it again. This was the case during the 1900 Olympic Games in Paris. 

However, a sewage problem last summer led to the cancellation of a pre-Olympic swimming event and it raised alarm bells. Macron is not the first French politician to promise to swim in the Seine. Paris mayor Anne Hidalgo and her predecessor Jacques Chirac also promised to do so "in the presence of witnesses", but never did.

For all these reasons, swimmers, including the Brazilian, are worried. "If it is not possible to compete there, there has to be a Plan B. The organisation has to accept that perhaps, unfortunately, it may not be able to hold the event where it wants to and it has to be concerned about the health of the athletes, which is the most important thing," explained Cunha.

The champion admits that "nothing can be done on the day of the event". This is a clear reference to the fact that the problem must be solved in advance, because if the athletes fall ill afterwards, it will be too late. It is not just the water in the Seine that is at risk, there are other, more global problems with climate change. "Everything is linked to what we have done to nature. In the case of the Games, I think it also has to do with the structure: The Seine was not made for swimming".

Finally, from a purely sporting point of view, Cunha knows that expectations are very high for her. But she doesn't mind, she knows it. She is "quite calm" despite having undergone shoulder surgery in 2022. If this could be her last Olympic Games, she doesn't even want to hear about it: "I don't want to have a date to stop."