Former Alaska Gov. Sarah Palin (R) said she could conceive of a third party in U.S. politics if newly elected Republicans stray from their principles.

Palin, the 2008 GOP vice presidential nominee and potential candidate for president in 2012, said the next two years will be some Republicans' "last shot" to prove themselves as authentic conservatives.

"Some in the GOP, it's their last shot," Palin said Monday evening on Fox News. "It's their last chance, and we will lose faith and we will be disappointed and disenchanted from them if they start straying from the bedrock principles that can grow our economy.

"If they start straying, then why not a third party?" the former governor added. "That's what people are going to start asking."

Palin's led the crop of conservative, insurgent Tea Party activists who have challenged establishment incumbents and candidates in the GOP this cycle. She's been particularly effective in Senate races, where candidates like Joe Miller (Alaska), Sharron Angle (Nev.) and Christine O'Donnell (Del.) won their primary races.

The GOP is expected to make major gains in the elections two weeks from now, setting up the possibility that it will reclaim the majority in the House and possibly the Senate, too.

Palin's not the only prominent conservative and potential GOP candidate for president to suggest that a third party in U.S. politics, possibly born of the Tea Party movement, could emerge if Republicans don't deliver on their pledges.

"If we do not govern according to our principles and if we don't follow through on the things we say we're going to do, I think there will be a third party in this country," Sen. John Thune (R-S.D.) said earlier this month on C-SPAN.