Barbara Comstock’s campaign for a congressional seat in Northern Virginia will receive a fundraising boost from the 2012 GOP presidential candidate. (Yue Wu/The Washington Post)

Mitt Romney will headline an event for Virginia congressional candidate Barbara J. Comstock next month, part of the 2012 presidential candidate’s reemergence as a prominent Republican fundraiser.

Comstock, a state delegate from Fairfax County, is campaigning for the Northern Virginia congressional seat being vacated by Rep. Frank R. Wolf (R); she will face Democrat John W. Foust, a Fairfax county supervisor, in the fall.

The fundraiser is scheduled for Sept. 30 at the home of Bobbie Kilberg, chief executive of the Northern Virginia Technology Council, and her husband, Bill Kilberg. Details have not been ironed out, but a spokeswoman for Comstock’s campaign said Romney campaign veterans will be present along with other donors.

Kilberg, a longtime Republican aide and donor, held a fundraiser for Romney at her home early in the 2012 Republican primaries.

During the 2013 campaign for Virginia governor, Democrat Terry McAuliffe tried unsuccessfully to win the endorsement of the NVTC’s political arm, Tech PAC. The group decided to support Republican Ken Cuccinelli II, even though Kilberg and another executive committee member had been critical of his campaign. McAuliffe, the eventual winner of the election, was said to have disappointed the group in an interview.

Romney endorsed Comstock on Twitter the day she announced her run for Congress. He has become increasingly popular with Republicans on the campaign trail this year, stumping and raising money for New Hampshire Senate candidate Scott Brown, Virginia Senate candidate Ed Gillespie, the New Jersey Republican Party and several national Republican committees. He also has waded into contested primaries, backing Rep. Mike Simpson for reelection in Idaho, Gov. Matt Mead for reelection in Wyoming and state Sen. Joni Ernst’s run for U.S. Senate in Iowa.

Financial reports released in July showed Foust outpacing Comstock in fundraising during the previous three months. He had about twice as much money on hand as his Republican rival, including $400,000 that he lent his campaign. The race for the district is expected to be one of the most expensive in the nation.

Romney’s former running mate, Rep. Paul Ryan (R-Wis.), is scheduled to headline a separate fundraiser for Comstock on Sept. 9. Many alumni of the 2012 presidential campaign are expected to be in attendance, including chief of staff Matthew Rhoades, political director Rich Beeson, adviser and spokesman Kevin Madden, lawyer Benjamin L. Ginsberg and more than a dozen others.