Such a seismic move would have profound consequences for Olympic and Paralympic sport, and be a crushing disappointment for athletes across the world, so what forces could prove decisive over the coming weeks?

New year, new doubts

So far, Japan has escaped the worst of the coronavirus pandemic, with far fewer deaths than the tragic numbers suffered in other parts of the world.

But once a state of emergency was declared in its capital two weeks ago following a record number of cases, and with public opinion appearing to turn against the Games, the sense of crisis intensified.

Olympic legend Sir Matthew Pinsent became the highest-profile former athlete to call for a cancellation, saying the idea of thousands of people flying round the world to gather, unvaccinated, in one place, was “ludicrous”. Tokyo, he suggested, should stage the Games in 2024 instead, with subsequent hosts Paris and Los Angeles both shifted back four years to accommodate the rejig.

With worries that the Games could worsen the country’s pandemic, Taro Kono then became the first Japanese cabinet minister to break ranks, admitting “anything could happen”, a message reinforced by senior IOC member Dick Pound, who said he too could not be certain it would go ahead.

With the controversy surrounding the build-up to the Australian Open in Melbourne showing the difficulties of navigating quarantine rules before a major international sports event, London 2012 boss Sir Keith Mills added his voice, telling BBC Radio 5 Live that he believed the Olympics were now “unlikely” to be staged this year.

The doubts swirling round Tokyo 2021 reached a new peak last week when the Times reportedthat, according to an unnamed Japanese government source, ministers had privately conceded the event would have to be cancelled, and they would now focus on securing the next available slot in 2032.

The fightback

Spooked by the story, apparently furious organisers pushed back uncharacteristically hard, a series of statements from the Tokyo 2020 committee, the Japanese government, the IOC and the International Paralympic Committee (IPC) all insisting the Games would still be happening as planned.

Insiders suggested there was a suspicion that, with a general election due in October, Japanese domestic politics may be behind the story.

Whether that is the case or not, expect more expressions of confidence when IOC president Thomas Bach addresses the media on Wednesday. Certainly few expect him to take up Florida’s presumably tongue-in-cheek offer for him to consider relocating the Games to the sunshine state.

Last week, Bach said there was currently “no reason whatsoever” to believe the Games would not start as planned in July, and that there was no need for a ‘Plan B’.

A sense of deja vu surrounded Bach’s upbeat tone. Almost 11 months ago, in the lobby of the organisation’s headquarters in Lausanne, I listened as the German defiantly made similar comments, insisting the words “cancellation and postponement” had not even been discussed by his executive board, despite such a move seeming inevitable.

Less than three weeks later, the Games were duly postponed, with the IOC criticised for what appeared to many to be a lack of transparency and clarity prior to the announcement.

On Friday, in the wake of the Times report, Bach spent time trying to reassure national Olympic committees around the world – and by extension sponsors and broadcasters – that he was adamant the Games would proceed. According to those on the conference call, he dismissed the story as “fake news”.

What is at stake?

It is no surprise there is such a determination to make Tokyo happen.

Three-quarters of the IOC’s revenue comes from broadcast deals for the Olympics. Almost all the rest comes from sponsorship linked to the event. In turn, the international sports movement relies on the money the IOC then distributes.

Insurance is understood to give the IOC significant protection against some losses in the event of a cancellation, and the organisation can fall back on its reserves. But with mounting controversy over China’s hosting of next year’s Winter Olympics, with campaigners putting pressure on the IOC’s sponsors over the country’s alleged persecution of Uighur Muslims, many would be much more comfortable with Tokyo hosting the first post-Covid Games than Japan’s rivals and neighbours in Beijing.

With billions of pounds having been spent on the renegotiation of contracts and added security measures, taking the overall official cost up to more than £11bn (and a lot more if some reports are to be believed), and national pride on the line, no wonder the Japanese government is so determined to press on, even if recent polls suggest significant unease among the public.

But some are not convinced by the certainty and confidence that Bach seeks to project. Not after his comments last year. Not when Japanese hospitals are now struggling to cope with the demand on beds and the country has closed its borders to visitors. Not when the country is not due to even start vaccinating until late February, with the roll-out even slower in less developed parts of the world. And not when there is such concern around more transmissible variants of the virus.

The ‘playbooks’

In an in-house video released by the IOC last week, Bach did acknowledge that work was continuing on “all potential scenarios” from immigration and quarantine rules, to social distancing in the Olympic Village, and even the possible absence of spectators.

Many would prefer Bach to go further and take a similar approach to that of Lord Coe, the head of World Athletics, who told my BBC colleague Alex Capstick last week that while he was convinced that organisers remained committed to the Games, he could not be certain they would happen. And how could he be? One thing this crisis has shown us repeatedly is that the situation can change rapidly, and that plans can change.

But talk to organisers and their resolve and confidence seems genuine.

Last week, the IPC gave some clues as to why, its statement referring to “countermeasures and plans which we believe will mitigate the risk”.

Next week ‘playbooks’ are expected be published, laying out in detail the personal responsibilities each person attending the Games must follow.