A price tag of JPY ¥155 billion (£800 million/€1.1 billion/$1.3 billion) has now been decided upon, down from the initial plan for a JPY ¥252 billion (£1.35 billion/€2.08 billion/$1.85 billion) stadium scrapped by Japanese Prime Minister Shinzō Abe in face of mounting public opposition as costs soared.

Capacity will be reduced from 80,000 to 68,000.

Zaha Hadid Architects (ZHA), the British-based firm that designed the abandoned plans, have reacted to the announcement by warning against the dangers of cutting costs too much, predicting how expensive rennovation would be required in the future.

Contractors for designing and constructing the Stadium will be chosen in late December ahead of the start of building-work 12 months later at the end of 2016, with Zaha Hadid among those vying for the contract.

The new plans must "convey Japan's exquisite tradition and culture to the rest of the world" while also blending into the historical environment, such as by using wooden materials where possible.

It calls for a "realistically best plan" while pursuing the cost-cutting effort, with a partial roof to be installed just above the spectator seats.

Concerns have since been raised about the tight deadline, with the Government having said there is no chance of the stadium being ready to host matches during the Rugby World Cup in 2019. 

The International Olympic Committee (IOC) had requested the January completion date, leading organisers to warn earlier this week the Stadium was unlikely to be finished by then, suggesting March, just six months before the Tokyo 2020 Opening Ceremony, was a realistic target.

The latest plans, however, stipulate the Stadium must be ready by April but also with the added condition of "seeking out technological proposals" that would allow for moving up the completion date to the end of January 2020.

“We welcome this announcement, this is a national project that will continue to deliver for Japan long after the Olympic Games are over and we understand the authorities’ desire to scale back the project and reduce costs," said IOC Coordination Commission chair John Coates.

"The revised seating capacity of 68,000 is more than adequate for the Olympic Games.

"It will also have an ability to accommodate extra seats with a total seating capacity to 80,000 in the future.

"We are particularly pleased that the authorities have listened to a request from both myself and the President of the Organising Committee Mr [Yoshirō] Mori to bring forward the completion date to January 2020.

"As we advised during a meeting earlier this week, at least six months is needed for additional overlay in the Stadium, technical installation, Olympic Broadcasting preparations and rehearsals for the Opening Ceremony.”

Zaha Hadid have announced that if they are chosen to adopt the new plan they could still complete the work in 2019, so that the Stadium would be ready well in time for the IOC requirements, as well as in time for the Rugby World Cup.

Their new design would include no air conditioning for spectator seating, as well as a smaller capacity than the original 80,000 proposed.

In a statement today, they have again claimed "developing the existing design with revisions and competitive bidding from construction contractors is the most cost-effective way to create a new National Stadium for Japan that delivers for the 2019 Rugby World Cup, Tokyo 2020 Games and the Japanese people in the long term".

It adds: "It is questionable whether a number of other changes to the brief and budget, which is set well below what contractors estimate it would cost to build a Stadium in Tokyo, would deliver a building that is a worthwhile or sustainable investment."

The London 2012 Olympic Stadium is cited as an example of the risks of attempting to build a "low-cost stadium with significant temporary elements", due to the rennovation work subsequently required.

"Building on the existing design and investment with a realistic budget would ensure that Japan has a National Stadium of the highest quality, standards and value for money that can host a range of community, national and international sporting events for the next 50 to 100 years," Zaha Hadid's statement added.

"ZHA has presented the detail of the design for the National Stadium and set out the risks of wasting this design work in favour of a rushed design that could produce a lower quality venue that is not ready on time for the 2020 Games, and requiring significant further investment and subsidies throughout its lifetime.”

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