Rep. Michele Bachmann (R-Minn.) will officially endorse Mitt Romney at a campaign event in Virginia on Thursday.
Bachmann, the founder of the Tea Party Caucus in Congress, suspended her own presidential campaign in January shortly after finishing in sixth place in the Iowa caucuses.
She is expected to announce her endorsement at a 1:15pm campaign event in Portsmouth, Va., The Virginian-Pilot reported, citing state GOP officials.
The endorsement will signal a strong change in Bachmann's view of the presumptive GOP presidential candidate. On the campaign trail, she was critical of the health care plan Romney enacted as governor of Massachusetts.
In December, when Bachmann's campaign was declining and she sought to revive it with a strong showing in Iowa, she wrote off Romney as being incapable of defeating Barack Obama.
"No he cannot beat Obama because his policy is the basis for Obamacare," she told ABC News then. "The signature issue of Obama is Obamacare. You can't have a candidate who has given the blueprint for Obamacare. It's too identical. It's not going to happen."
Bachmann, 56, has represented Minnesota's 6th congressional district since 2007 and has said she will run for another term this November.