The International Olympic Committee (IOC) wraps up its final planning sessions tomorrow with Tokyo Olympic organisers, just two months before the Games are to open.
Much of the focus is on persuading a sceptical public and medical community the Games should go ahead.
"We have much to do over the next three days," IOC vice president John Coates said on Wednesday as the sessions began.
The core problem is that 60 to 80 per cent of people in Japan, depending how the question is asked in public opinion polls, don't want the postponed Olympics to open in the middle of a pandemic despite repeated assurances from organisers the Games will be "safe and secure".
There is no indication so far the Games will be cancelled. The IOC has repeatedly said they are going ahead.
But the IOC's most senior member, Richard Pound, in an interview with Japan's JiJi Press, said the final deadline to call it off was still a month away.
"Before the end of June, you really need to know, yes or no," JiJi quoted Pound as saying. Pound repeated — as the IOC has said — that if the Games can't happen now they will be cancelled, not postponed again.
Kaori Yamaguchi, a bronze medalist in judo in the 1988 Olympics and a member of the Japanese Olympic Committee, hinted in an interview with Japan's Kyodo news agency this week that organisers were cornered. She has been sceptical about going ahead.
"We're starting to reach a point where we can't even cancel any more," she said.
Tokyo, Osaka and many other prefectures are under a state of emergency and healthcare systems are being stretched. Emergency measures are to end on May 31, but they are likely to be extended and approach the July 23 opening date.
"If the current situation continues, I hope the government will have the wisdom not to end the emergency at the end of May," Haruo Ozaki, head of the Tokyo Medical Association, told the weekly magazine Aera.
Ozaki has consistently said government measures to control the spread of Covid-19 have been insufficient. About 12,000 deaths in Japan are attributed to the virus, and the situation is exacerbated since few in Japan has been fully vaccinated.
Ozaki warned if the emergency conditions are not extended, the virus and contagious variants will spread quickly.
"If that happens, there will be a major outbreak, and it is possible that holding the Games will become hopeless," he added.
Ozaki is not alone with this warning.
The 6000-member Tokyo Medical Practitioners' Association called for the Olympics to be cancelled in a letter sent last week to Prime Minister Yoshihide Suga, Tokyo Governor Yuriko Koike, Olympic Minister Tamayo Marukawa, and Seiko Hashimoto, the head of the organising committee.
"We believe the correct choice is to cancel an event that has the possibility of increasing the numbers of infected people and deaths," the letter said.
"Stop Tokyo Olympics" campaign organiser Kenji Utsunomiya said he planned to deliver petitions on Friday with 375,000 online signatures to Tokyo organisers and Suga. He delivered the petitions earlier to Tokyo Governor Yuriko Koike.
IOC president Thomas Bach, aware Japan's medical system is stretched, said on Wednesday national Olympic committees could provide "additional medical personnel" to aid Japan.
He gave no details, but this move would also add to the burdens on national Olympic committees, many of which are struggling to meet guidelines to enter delegations into Japan.
Bach had to cancel a trip to Japan this month because of the virus, but is expected to arrive in Japan in July, just days before the Olympics open.