LONDON (Reuters) - British Prime Minister Gordon Brown will announce on Tuesday that a parliamentary election will take place on May 6, a source in the ruling Labor Party said on Monday.

Brown will announce the election date after meeting Queen Elizabeth to seek the dissolution of parliament, the source said. He is expected to request that parliament be dissolved on April 12, allowing a few days to complete essential business, the source said. Opinion polls suggest that Labor, in power since 1997, is on course to lose the election to the Conservative opposition, but analysts say the vote could go either way or even result in a rare minority government.

(Reporting by Matt Falloon, editing by Tim Pearce)