Tokyo city's top official has compared the government to the Japanese Imperial Army during World War II after being asked to pay over $400 million towards the cost of the 2020 Olympic stadium, local media reported on Monday.

Sports Minister Hakubun Shimomura also proposed further scaling back plans for the showpiece venue, including scrapping the retractable roof, in a bid to control escalating costs.

But his decision to lobby Tokyo for almost 30 percent of the estimated total construction bill of US$1.4 billion for the new National Stadium enraged Tokyo Governor Yoichi Masuzoe, who blasted the government as "irresponsible" for making the demand.

"The figure being mentioned is around 50 billion yen ($418 million)," Masuzoe was quoted as saying by the Nikkan Sports daily. "Up until now there has been absolutely no communication about this. It is irresponsible because we have to think of the taxpayers."

Masuzoe added: "It's irresponsible to keep repeating 'we can build it.' But that's just like the Japanese Imperial Army during the war saying 'we're winning, we're winning' -- when in fact we were losing."

Shimomura wants to wait until after the Olympics to add a retractable roof and also called for around 30,000 of the stadium's 80,000 seats to be temporary ones to reduce the financial burden and speed up construction so that it is ready in time for the 2019 rugby World Cup, to be hosted by Japan.

"We have been in talks with the contractors," said Shimomura. "We hope to present a precise budget and plan by the end of the month. We would like Tokyo to contribute to the costs of building the stadium."

Masuzoe was left fuming after his meeting with the minister, reiterating his stance that Tokyo should not be asked to pay for a national stadium, raising the issue of ownership if both sides failed to reach an agreement.

"We obviously can't just not build an Olympic stadium because the government can't (finance it)," he said. "If the country can't then we have to examine the possibility of building it as a municipal stadium."

The 2020 Olympic stadium has faced two years of widespread criticism, with prominent Japanese architects launching scathing attacks on Iraqi-British architect Zaha Hadid's futuristic designs, and the budget was subsequent slashed by 40 percent.

The iconic National Stadium, built for the 1964 Tokyo Olympics, was recently demolished and construction on the new venue is scheduled to begin in October.
Source: AFP