Majority Leader Eric Cantor said Wednesday he would surrender his No. 2 leadership post in the U.S. House of Representatives, after suffering a crushing primary election defeat by a little-known and underfunded economics professor from the ultra-conservative Tea Party wing of the Republican party.

Cantor said he will serve out the remainder of his term in Congress. And he hopes to continue to be a champion for conservative causes across the nation after he leaves office.

Cantor refused to discuss how he lost the primary, telling journalists: "I’m going to leave the political analysis to y’all."

He did, however, attempt to play down the divide within the GOP between traditional Republicans and those aligned with the Tea Party movement, twice saying the difference between the two groups "pales in comparison" to the ideological gulf separating Republicans and Democrats. 

Cantor

There has been quiet pressure on U.S. House Majority Leader Eric Cantor to step down from his post as the Republicans' second-ranking leader following his primary loss. (J. Scott/Associated Press)

David Brat's double-digit and single-issue victory on Tuesday in Virginia — one of the most profound political upsets in recent American history — set in motion a major shakeup inside the Republican power structure, turning Cantor into a lame duck until his term expires at the end of the year.

Brat ran a campaign that focused on a fight against loosening immigration laws.

On Wednesday, House Republican colleagues began jockeying for position in the coming leadership shakeup.

Representative Kevin McCarthy of California was informing fellow Republicans he intended to run to succeed Cantor, officials said, and Representative Pete Sessions of Texas also signalled an interest.

Representative Steve Scalise was hoping to replace McCarthy in his current spot, officials said.

'Miracle from God'

The manoeuvring took place as Brat celebrated his triumph over Cantor in an upset that shocked the party establishment and handed tea party forces their largest victory of the primary season.

"This is a miracle from God," Brat said Tuesday night, in an appearance before supporters.

But as he looked ahead to November's elections, he declined to spell out policy specifics.

"I'm a Ph.D. in economics, and so you analyze every situation uniquely," he told MSNBC in an interview in which he said he preferred to keep the focus on the "celebratory issues" of Tuesday's results.

His allies sounded more than pleased. "The grassroots is in revolt and marching," said L. Brent Bozell III, chairman of ForAmerica.

The victory was by far the biggest of the 2014 campaign season for tea party forces, although last week they forced veteran Mississippi Senator Thad Cochran into a June 24 runoff and hope State Senator Chris McDaniel will achieve victory then.

Cantor's defeat was the first primary setback for a senior leader in Congress in recent years. Former House Speaker Thomas Foley of Washington and Senate Democratic leader Tom Daschle of South Dakota both lost their seats at the polls in the past two decades, but they fell to Republicans, not to challengers from within their own parties.

The outcome may well mark the end of Cantor's political career, although at 51 he has plenty of time to attempt a future comeback. Aides did not respond Tuesday night when asked if the majority leader would run a write-in campaign in the fall.

But the impact of Cantor's surprise loss on the fate of immigration legislation in the current Congress seemed clearer still. Conservatives will now be emboldened in their opposition to legislation to create a path to citizenship for immigrants living in the country illegally, and party leaders who are more sympathetic to such legislation will likely be less willing to try.

Many Republicans say the party can ill afford to stick to an uncompromising stand on the issue, given the increasing political influence of Hispanic voters.

With files from CBC News