Officials from the Japan Sport Council has conceded to public rage and announced it has decided to scale back the proposed 70-metre mammoth stadium intended for the Tokyo 2020 Olympics.

Protesters blasted the proposed stadium because it would tower other structures in the surrounding area in west Tokyo. Moreover, it contradicts the 15-metre height restriction in the area. The proposed stadium, with a futuristic, bike-helmet-shaped design, was designed by London-based Iraqi architect Zaha Hadid, said to be built at a cost of 300 billion yen (AU$3.2 billion).

International Olympic Commitee (IOC) President Thomas Bach (C) prepares to shake hands with IOC Vice President John Coates (L) and Japanese Olympic Committee President Tsunekazu Takeda during a photo session at a news conference in Tokyo November 20, 2013. Bach on Wednesday held a news conference in Tokyo, the host city of the 2020 Summer Olympics and Paralympics, and discussed the future of the Olympic and Paralympic Games. REUTERS/Issei Kato

It was intended to replace the existing 54,000-seat national stadium in an area surrounded with numerous parks and a large Shinto shrine.

On Tuesday, the Japan Sport Council said it would scale down the intended floor space for the stadium by one-quarter to 220,000 square metres. The body is responsible for the operations of the current and future stadium.

"While we are still using Zaha Hadid's design, we now plan to downsize it," the AFP quoted a JSC official as telling an expert panel which approved the new blueprint. JSC maintained the building will have an 80,000-seating capacity, a retractable roof and movable seats which will adjust based on the different sporting events that will take place in the stadium.

The resizing will slash construction costs to 180 billion yen (AU$1.9 billion). However, the JSC maintained the height estimates of the initial design.

But protesters said the toned-down costs remain above the government's earlier pronouncement of initial estimates for a new stadium.

Apart from the 2020 Olympics, Japan is also set to play host to the 2019 Rugby World Cup.