Democratic White House hopeful Martin O’Malley will vow Tuesday that if elected president, his administration would stop defending a decade-old law that provides legal immunity to gun dealers and manufacturers when their weapons are used in crimes, aides said.

That step is one of seven executive actions that the former Maryland governor plans to roll out at a campaign event in New Hampshire on an issue — gun control — that has become a point of contention between the two leading candidates for the nomination, Hillary Rodham Clinton and Sen. Bernie Sanders (I-Vt.).

In a memo, O’Malley’s campaign argues that the Protection of Lawful Commerce in Arms Act of 2005 effective gives “blanket immunity to merchants of death” and is unconstitutional. O’Malley would like to see the law repealed by Congress — a position Clinton also holds — but is pledging to do what he can to undermine it in the meantime.

Sanders voted the measure as a member of the House of Representatives, and it is one of a handful of votes that has allowed Clinton and O’Malley to portray him as weak on gun control.

Sanders has defended his 2005 vote but said he is opening to reconsidering the issue. More broadly, he says that the country needs to come together around “sensible” gun control measures to address the rash of violence of recent years.

Former secretary of state Hillary Clinton said Sen. Bernie Sanders (I-Vt.) is not tough enough on guns (CNN)

Clinton unveiled a new television ad Tuesday on gun control that will air in Iowa and New Hampshire, underscoring her campaign’s belief that the issue cuts in favor of the former secretary of state.

O’Malley, who is struggling to turn the Democratic contest into a three-way race, has previously proposed other gun-control measures that build on a package he championed in 2013 in Maryland as the state’s governor. The earlier measures include a requirement that everyone who purchases a gun gets a license and is fingerprinted.

Other measures O’Malley plans to unveil Tuesday include: requiring gun manufacturers that seek federal contracts to make design changes that enhance gun safety and help law enforcement track firearms; close regulatory loopholes that allow the sale of “cop-killer” bullets in some circumstances; and issue federal rules defining safety standards for gun-locking devices.

O’Malley plans to discuss his plans at a campaign event in Keene, N.H., on Tuesday evening. He is in the middle of his latest swing through the first-in-the-nation primary state and plans to formally file his candidacy there Wednesday morning.