Former congresswoman Gabrielle Giffords and her husband, Mark Kelly, attend a Hillary Clinton campaign event in Phoenix in March 2016. (Carolyn Kaster/AP)

Former congresswoman Gabrielle Giffords, an Arizona Democrat who became a prominent gun-control advocate after surviving a 2011 shooting, will stump in Virginia on Monday for Democratic gubernatorial candidate Ralph Northam.

Her political action committee, Americans for Responsible Solutions, also announced Thursday that it would spend $150,000 on digital ads and mailers to persuade voters to support Northam in his race against Republican Ed Gillespie.

Giffords is among several prominent Democrats to campaign for Northam. Hillary Clinton is scheduled to headline a Northam fundraiser in New York on Wednesday, and former president Barack Obama plans to campaign for him before the November election.

On Monday, Giffords and her husband, former astronaut Mark Kelly, will attend two roundtables, greet Northam volunteers at a field office and attend an evening reception for Northam supporters, according to officials at her PAC.

Her group spent at least $450,000 on Virginia elections in 2015, when Democrats mounted an unsuccessful effort to take control of the state Senate.

Northam supports an assault-weapons ban, universal background checks and reinstating Virginia's one-handgun-a-month law governing weapon sales. Gillespie opposes further restrictions on firearms.

Americans for Responsible Solutions joins a crowded field of outside groups getting involved in Virginia's gubernatorial contest, the nation's only competitive statewide race this November.

Another gun-control group, the Everytown for Gun Safety Action Fund, has announced it would spend $1 million, including $250,000 on pro-Northam mailers.

Liberal groups including Planned Parenthood, the Virginia League of Conservation Voters, BlackPAC and billionaire environmentalist Tom Steyer's NextGen America are sending mail or canvassers to Virginia homes, while Americans for Prosperity, the group financed by the billionaire industrialists Charles and David Koch, has launched anti-Northam mailers and commercials.

Virginia general election guide

The National Rifle Association has aired commercials attacking Virginia Attorney General Mark R. Herring (D) in his bid for reelection and is expected to support Gillespie, but a spokeswoman for the organization declined to discuss its campaign strategy.