A prominent Japanese architect says the spaceship-like main stadium approved for the 2020 Tokyo Olympics is too big.

Fumihiko Maki says it's overly expensive and would clash with the surroundings. His office says he has the support of 100 other well-known people in Japan.

Maki stresses that he isn't criticizing the design by award-winning British-Iraqi architect Zaha Hadid — just the size.

The 80,000-seat stadium would dwarf one of Maki's nearby creations: the 1990 Tokyo Metropolitan Gymnasium.

The government has already approved the stadium, but construction isn't slated to begin until next year.

Zaha Hadid Architects director Jim Heverin says the new stadium will fit into an area that's already a mix of styles and structures big and small. He welcomes the debate, though, saying: "Design is subjective."