Revealed: Club for Growth is main donor to gun-toting Republican congressman

The Club for Growth, an anti-tax group funded by billionaires, has been the primary financial backer of Andy Harris, the Republican lawmaker who sought to bring a gun to the floor of the House of Representatives.

Harris, a medical doctor who represents the eastern shore of Maryland, has received about $345,000 from individuals associated with the Club for Growth since the rightwing campaigners helped to get him elected in 2010, according to the Center for Responsive Politics.

Related: Billionaires backed Republicans who sought to reverse US election results

The latest revelation about the Club for Growth’s support for Harris comes after the Guardian revealed last week that the group, which is headed by the former Republican congressman David McIntosh, was a major financial support of 42 of the Republicans who sought to invalidate Joseph Biden’s victory in the 2020 election.

It has also supported another lawmaker, Lauren Boebert, who has argued for the need for firearms to be carried inside the US Capitol. Members may only carry firearms in their own offices.

CNN reported on Friday that the US Capitol police were investigating an incident that occurred on Thursday, when Harris was stopped from bringing a concealed weapon on to the floor of the House. The Republican, who is an anaesthesiologist, had set off the newly installed metal detectors outside the chamber, prompting him to ask another lawmaker, Republican John Katko, to hold the weapon for him.

Katko refused, according to a press pool, and Harris then left and returned later, without setting off the metal detector.

Bryan Shuy, Harris’s chief of staff, said in a statement released to the Guardian: “Because his and his family’s lives have been threatened by someone who has been released awaiting trial, for security reasons, the congressman never confirms whether he nor anyone else he’s with are carrying a firearm for self-defense.”

Shuy added: “As a matter of public record, he has a Maryland handgun permit. And the congressman always complies with the House metal detectors and wanding. The congressman has never carried a firearm on the House floor.”

The Club for Growth did not respond to a request for comment.

The Club for Growth became a significant backer of Harris in 2007, when it helped to defeat a longtime – and more moderate – Republican congressman who had served in Maryland’s first district. Harris lost that race in the general election but then won in 2009 in a heavily Republican district.

In a CNN interview on Thursday, the Democratic congresswoman Alexandria Ocasio-Cortez, who has said she feared for her life on the day of the Capitol insurrection, said “a lot” of members of the House did not yet feel safe around other members.

“The moment you bring a gun on to the House floor in violation of rules, you put everyone around you in danger. It is irresponsible, it is reckless, but beyond that it is the violation of rules,” she said.

She added that Harris’s actions, whatever his intentions, had endangered the lives of fellow members of Congress and were a violation of House rules.

The Club for Growth has recently received the vast majority of its funding from Richard Uihlein, the anti-choice rightwing billionaire founder of Uline packaging supply company, and Jeffrey Yass, a billionaire co-founder of Susquehanna International Group, a Philadelphia-based options trading company.

Last year, the group spent millions of dollars helping to elect Lauren Boebert, a far-right pro-gun activist and QAnon conspiracy theorist, who this week was reported to have challenged Capitol police officers who sought to check her purse after she set off metal detectors.

Harris voted on 6 January to overturn the 2020 election results, hours after rioters stormed the US Capitol. In a a radio broadcast a few days later, he criticized a decision by Twitter to ban the president from using the online platform, calling it the result of collusion between socialists and big corporations.

In fact, some of the richest Republican donors have backed Harris, including the billionaire Steve Schwarzman and other executives from Blackstone, the Wall Street firm whose executives donated more than $10,000 to Harris in the last election cycle.