A revised plan for Japan's new stadium for the 2020 Olympics is still so wasteful and large for the site that it's a "sin" — one that destroys the power of the original design, a Tokyo architect running a petition drive against the structure said.

The spaceshiplike stadium was designed by Zaha Hadid, who also designed the aquatics center for the 2012 London Olympics, but the plans came under fire soon after Tokyo won the right to host the games last year, for ballooning cost estimates and a lack of harmony with the surrounding cityscape.

This week, the Japan Sports Council released a new design proposal reducing the size of the stadium by more than 20 percent and cutting costs from some ¥300 billion, more than twice the original bid estimate, to roughly ¥162 billion.