According to the Kyodo news agency, leaders from 10 local Governments have written to Tokyo Governor Yuriko Koike urging her not to backtrack on a promise made by the Metropolitan Government in 2013.

The policy said the Organising Committee for the Games should bear the brunt of the costs for building temporary venues.

Heads of the five prefectures of Chiba, Kanagawa, Miyagi, Saitama and Shizuoka as well as Hokkaido and the cities of Chiba, Saitama, Sapporo and Yokohama penned the letter to Koike, who has already seen some of her cost-cutting measures, including switching sports to cheaper venues outside of the city, scrapped in favour of the initial plans.

Earlier this year, the Metropolitan Government and Tokyo 2020 agreed to review this policy.

In September, a task force, appointed by Koike, warned that drastic changes must be taken to avoid the budget ballooning to ¥3 trillion (£20 .7billion/$25.5 billion/€24.5 billion).

This included a recommendation that local and Municipal Governments would help pay for temporary venues to be constructed.

According to the letter, a "growing sense of unease" is evident within the "municipality organisations", some of whom are led to believe the original agreement signed in 2013 remains in place.

"We believe that the policy adopted when bidding for the Games remains unchanged," Kanagawa Governor Yuji Kuroiwa was quoted as saying by Kyodo when delivering the letter to Koike.

Kiyoshi Ueda, the Governor of Saitama, went a step further and claimed he was "offended" by "various talk going on about costs even though no-one has come to us yet for a formal consultation".

In response, Koike claimed they would "make every effort to consider what the Tokyo Metropolitan Government can do" while revealing she would decide by the end of the fiscal year - March 31 - on how costs will be shared.

It represents the latest blow to Koike’s plans for the Tokyo 2020 Olympics, which have come under fire amid fears of rising costs and a budget described by the International Olympic Committee as giving the "wrong impression" to cities who may wish to bid for the Games in future.

Tokyo 2020 have sought to play down concerns over spiralling costs since, although the Task Force sparked further fears when they proposed venues for four sports - swimming, rowing, canoeing and volleyball - be moved to address the issue.

All these plans were then dropped after Koike claimed the venues would not cost as much as first thought.

Organisers last week unveiled a budget of between ¥1.6 trillion (£11 billion/$13.6 billion/€13.1 billion) and ¥1.8 trillion (£12.4 billion/$15.3 billion/€14.7 billion).

The official cost estimate, revealed during a Four-Party Political Working Group meeting, is down from the maximum budget cap of ¥2 trillion (£13.8 billion/$17 billion/€16.4 billion) cited by Tokyo 2020 President Yoshirō Mori last month.