A group of third-party candidates and parties is suing the Federal Election Commission (search), alleging wrongful dismissal of their case against the Commission on Presidential Debates (search).

The lawsuit, filed Wednesday in federal court in the District of Columbia, says the debate commission is partisan and, under federal law, should not be allowed to use large amounts of corporate money to benefit Republican and Democratic candidates and their parties.

In March, the FEC dismissed the group's original complaint against the commission. The group had sought to block it from sponsoring debates, claiming a bias toward Democrats and Republicans. Federal law requires the commission to be nonpartisan.

Independent presidential candidate Ralph Nader (search) was among those filing the suit, along with former Reform Party candidates Pat Buchanan (search) and John Hagelin (search), the Constitution Party and the Green Party. The National Voting Rights Institute (search) is helping represent the plaintiffs.

The FEC does not comment on pending litigation. Janet Brown, executive director of the Commission on Presidential Debates, had not seen the lawsuit and declined t comment. She said the panel is in full compliance with FEC regulations.