Opposition parties to Kyriakos Mitsotakis' ruling New Democracy party in Greece have reacted furiously to the revelations first reported by Politico.

Citing a senior official familiar with the matter, Politico reported that Saudi Crown Prince Mohammed bin Salman discussed the officer with Mitsotakis in a private conversation last year.

Another source said that Saudi Arabia would "fully underwrite the costs" for Greece and Egypt of staging the World Cup in exchange for hosting 75 per cent of the fixtures.

Neither Greece nor Egypt have said whether such an offer was taken up, and Greek Deputy Sports Minister Lefteris Avgenakis claimed that the report was "full of inaccuracies" and the tri-continental bid is "still in the early stages".

A Sports Ministry spokesperson disputed the claim that "the Crown Prince suggested to the PM that Saudi Arabia would bear the costs of the event", as reported by Politico.

The left-wing opposition party Syriza has called for greater transparency, and pointed to its proposal for a bid with Bulgaria, Romania and Serbia when it was in Government until 2019.

"Let's find out why Greece gives the strong brand name of a European country that is synonymous with freedom and democracy in this proposal with Saudi Arabia", Syriza said.

Another left-wing party, MeRA25, admitted the report was "extremely worrying" and called for "no collusion with this murderous regime" nor "the dictatorial regime of Egypt".

Mitsotakis' conservative Government has established strong ties with Saudi Arabia.

Greece has provided arms and troops to Riyadh, the Prime Minister has travelled to the Saudi capital on multiple occasions, and Athens last year became the first European capital visited by bin Salman since the state-ordered assassination of journalist Jamal Khashoggi in 2018.

A Saudi-led tri-continental World Cup bid is expected to face competition from Spain, Portugal and Ukraine in Europe and Argentina, Uruguay, Paraguay and Chile in South America, with a decision expected at the FIFA Congress next year.

FIFA reformed its procedure for awarding the World Cup process after the disputed and highly-controversial double award of the 2018 and 2022 editions to Russia and Qatar respectively, with the Congress now selecting a host.

The double award in 2010 is widely viewed as contributing to the fall of disgraced former FIFA President Sepp Blatter in 2015.

Qatar's staging of the first Middle Eastern World Cup was overshadowed by criticism of its human rights record, and the host nation has been implicated in a high-profile bribery scandal at the European Parliament with it and Morocco accused of paying bribes to officials in exchange for influence.

Qatar has denied funnelling money to gain influence.

Last year's World Cup was moved to the northern hemisphere's winter for the first time because of Qatar's heat and humidity, and a similar move would likely be necessary for a bid including Saudi Arabia.

Two of football's all-time biggest stars in Portugal's Cristiano Ronaldo and Argentina's Lionel Messi are expected to boost the Saudi bid.

Ronaldo has recently signed for Saudi club Al Nassr on a deal reportedly worth £175 million ($212 million/€198 million) per year, while Messi was unveiled as a tourism ambassador or the country last year.

Saudi Arabia has proved a destination of note for numerous professional boxing fights, is a Formula One Grand Prix host and has been awarded several multi-sport events.

These include the 2034 Asian Games, this year's World Combat Games, the 2025 Asian Indoor and Martial Arts Games, and the 2029 Asian Winter Games.

The latter event in the yet-to-be-built resort of Trojena has proved particularly controversial given Saudi Arabia is the world leader in exports of crude oil, and has led to accusations of "greenwashing".

The FIFA World Cup has long been mooted as a target for Saudi Arabia, although initial reports of a project with Italy failed to materialise.

FIFA President Gianni Infantino appears to enjoy a friendly relationship with bin Salman watching Ukrainian Oleksandr Usyk defend his heavyweight boxing world titles against Briton Anthony Joshua in Jeddah last this year.

He also watched the opening match of the 2022 World Cup alongside the de facto Saudi leader for the second consecutive edition.

It was the Saudi Arabian Football Federation which formally proposed exploring the possibility for FIFA to stage its men's and women's World Cups every two years rather than every four in May 2021, although this idea has lost momentum in light of stiff European and South American opposition, and Infantino distanced himself from the proposal at this year's Congress.

FIFA has sparked controversy over a rumoured sponsorship deal with Visit Saudi for the 2023 Women's World Cup in Australia and New Zealand, with Football Australia saying it was "very disappointed" having not been consulted.

Critics of the bin Salman regime have accused Saudi Arabia of sportswashing and seeking to distract from its record on human rights, including the assassination of Khashoggi, its role in the bombing in Yemen, harsh restrictions in place on women's rights and its use of the death penalty.

None of Saudi Arabia, Greece and Egypt have previously staged the World Cup, although Athens held the Olympic and Paralympic Games in 2004.

The men's World Cup is set to expand from 32 to 48 teams from 2026.