More than 1,000 people filed a lawsuit against the government on Friday, seeking to halt Japan's involvement in 12-country talks on a Pacific Rim free trade agreement, which they called "unconstitutional."

A total of 1,063 plaintiffs, including lawmakers, claimed in the case brought to the Tokyo District Court that the proposed Trans-Pacific Partnership would undermine their basic human rights under the Constitution.

The lawsuit is led by Masahiko Yamada, 73, a lawyer who served as agriculture minister in 2010 as part of the Democratic Party of Japan government.