Not quite ready to give up on her presidential ambitions, comedian Roseanne Barr is joining up with activist Cindy Sheehan for a new run at the White House.

Fox News has learned that over the past few days Barr asked Sheehan to join her in an attempt to win the little-known Peace and Freedom Party's line on the California ballot.

A party official told Fox News that Barr, who failed in her attempt earlier this year to win the Green Party nomination, has a "fairly high chance" of securing the spot after she again reached out to Peace and Freedom leaders several weeks ago. This was something her campaign explored months ago, but Green Party rules forbid crossover nominees so Barr abandoned that effort.

Now that the Green Party process has played out, Barr renewed her interest with the Peace and Freedom folks and was told she needed a running mate. Several days ago Cindy Sheehan, a party member who gained notoriety for her opposition to the Iraq war, agreed to join Barr.

Sheehan will speak Friday night on behalf of the ticket at the party's nomination convention. Barr will speak Saturday shortly before party leaders vote on their nominee.

Barr lost the Green Party nomination but has updated her website, roseanneforpresident2012.org, to reflect the change toward the Peace and Freedom nomination. "She is the lone voice of courage and reason who is unstoppable as she holds corporate-funded politicians feet to the fire," the page declares. In an interview with Fox News earlier this year, Barr talked about the difficulty of running for office.

This campaigning stuff is really grueling," she said. "If you didn't really believe in what you were doing, I don't know why you'd want to do it, you know."

Since the Peace and Freedom Party doesn't have a national presence the nominee from California is unlikely to appear on most November ballots elsewhere.

According to the party's website, it was founded in 1967 and advocates free education, abortion on demand and "is committed to socialism, democracy, ecology, feminism and racial equality."