Go Cindy!

(CNN) — Despite swearing off public life earlier this year, peace activist Cindy Sheehan would run against House Speaker Nancy Pelosi as an independent in 2008 unless the speaker moves to impeach President Bush, a Sheehan spokeswoman said Sunday.

Sheehan, a northern California resident, is taking part in a protest caravan from President Bush’s home in Crawford, Texas, to Washington, which is scheduled to arrive July 23. Spokeswoman Tiffany Burns told CNN that Sheehan would challenge the speaker, who has held her San Francisco-area seat since 1987, unless Pelosi introduces articles of impeachment before then.

There was no immediate reaction from Pelosi’s office to Sheehan’s threat. The speaker said in November that calls for impeaching Bush were “off the table,” but that Congress would push for an end to the widely unpopular, 4-year-old war under Democratic control.