(FOXNEWS) — Eric Cantor plans to step down as House majority leader at the end of July after suffering a shocking primary defeat to a Tea Party-backed challenger, Fox News has learned.

Cantor, following his loss to primary rival Dave Brat, plans to tell colleagues about his plans at a House Republican Conference meeting set for 4 p.m. ET.

Several House members already are jockeying for position, making phone calls and lining up for a potential leadership race.

“Members are freaking out right now,” one senior House GOP source told Fox News, noting that nothing “rattles” lawmakers more than phone calls about who might support whom.

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