Former presidential candidate Michele Bachmann will endorse Mitt Romney on Thursday, a Romney campaign official confirmed to CNN.
Bachmann is set to appear with the presumptive Republican presidential nominee at an event in Portsmouth, Virginia at 1:15 p.m.
The Minnesota congresswoman has repeatedly said in recent weeks it was only a matter of time before she would officially back Romney.
As a candidate, Bachmann initially ran with large tea party appeal, frequently bucking what she described as the more establishment faction of the party that Romney represented.
Her endorsement comes weeks after former Pennsylvania Sen. Rick Santorum dropped out of the race, a move that essentially locked up the nomination for Romney.
Asked repeatedly why she was holding out in her support for Romney, Bachmann would not go into specifics but said she was working "behind the scenes, bringing together all factions of our party."
"As the line says in the 'Wizard of Oz,' 'All in good time, my pretty,'" Bachmann said on CNN's "The Situation Room with Wolf Blitzer" last week. "It will happen."