A group of Ralph Nader (search) supporters asked theSupreme Court (search) on Friday to keep the presidential candidate on Oregon's general election ballot.

In a late evening filing, the supporters asked the high court to review Oregon's decision to remove Nader because of flawed voter petition sheets. They argued that Secretary of State Bill Bradbury (search), a Democrat, improperly used unwritten rules to decide the validity of the petitions.

"His actions in applying unwritten rules, without notice or opportunity for the Nader campaign to comply with those rules, violated the right" to free speech and due process, the 52-page filing argues.

On Wednesday, the Oregon Supreme Court unanimously upheld Bradbury's determination that flawed petitions left Nader 218 signatures short of the 15,306 needed to put him on the Nov. 2 ballot, saying Bradbury acted within his authority.

Friday's filing, made by supporters whose signatures weren't recognized as valid, asked the Supreme Court to keep Nader on the ballot while it considers whether to hear an appeal of the Oregon ruling.

Nader backers have accused Bradbury, a supporter of Democratic presidential candidate John Kerry, of political bias. They said Democrats fear Nader could siphon votes from Kerry, as many believe he did in 2000 against former Vice President Al Gore.

In 2000, Nader drew 5 percent of the vote in Oregon as the Green Party nominee. Recent polls say that fewer than 2 percent of Oregon voters support Nader this year.

Nader is on the ballot in more than 30 states and is suing for ballot access in several others.