) -- Eric Cantor, the second-ranking Republican in the House, will step down from his post as majority leader after losing his primary bid Tuesday night, sources tell NBC News.
Aides say they expect Cantor to tell his colleagues he will resign from the position at a meeting of House Republicans at 4 p.m. ET.
Cantor, a Virginia Republican, has served as second-in-command to House Speaker John Boehner since 2010. He was defeated in the primary by David Brat, a little-known economics professor who ran a shoestring campaign without the support of prominent national Tea Party groups.
The decision, first reported by the Washington Post, is sure to send shockwaves through Capitol Hill as members of the conservative and establishment wings of the Republican Party jockey to fill the influential post.
Cantor had previously been discussed as a potential successor to Boehner if the current speaker stepped down.
Other top Republicans are already floating names to replace Cantor in the high-ranking post.
Rep. Pete Sessions, R-Texas, is actively discussing his interest in the majority leader job, a GOP aide confirmed to NBC News.
Rep. Jeb Hensarling of Texas, former GOP Conference Chairman and current Chairman of the House Financial Services Committee, is another favorite of conservatives for the job. In a statement Monday, Hensarling acknowledged that he's mulling a run.
"I am humbled by the many people who have approached me about serving our Republican Conference in a different capacity in the future. There are many ways to advance the causes of freedom and free enterprise, and I am prayerfully considering the best way I can serve in those efforts,” he said.