GOP Representative has emerged as outspoken critic of war on Iran and overseas military interventions.

United States Republican Representative Thomas Massie, an outspoken critic of the Trump administration’s war on Iran, has sought to force a long-shot vote in the US Congress on the impeachment of Secretary of Defence Pete Hegseth.

Massie read articles of impeachment against Hegseth in the US House of Representatives on Tuesday, accusing the Pentagon chief of waging war without congressional approval, carrying out extrajudicial killings, and paying little mind to civilian casualties in military operations.

“Secretary Hegseth abused the powers entrusted to him as secretary of defence by subordinating the constitutional limits on the use of military force and the laws governing the conduct of hostilities to his own policy objectives,” Massie said, adding that Hegseth has shown a “profound disregard” for the impact of US military operations on civilians.

The Pentagon chief has faced criticism for the US-Israel war on Iran and his record of disparaging remarks about protections meant to minimise civilian casualties and ensure adherence to the law by US forces, which he has dismissed as “stupid” and “politically correct” rules of engagement that hinder the military.

The resolution for Hegseth’s impeachment could receive a vote in the coming days, but faces long odds of success in the Republican-majority US House of Representatives.

The Pentagon has said that it supports Hegseth.

“The entire Department is unified behind the Secretary’s vision and will continue working to put our warfighters and America first,” Pentagon press secretary Kingsley Wilson told the news service Reuters in an emailed statement.

While polls show that most Republicans support the otherwise unpopular war on Iran, a handful of figures on the political right, including Massie and media personality Tucker Carlson, have become increasingly critical of the Trump administration’s interventionist foreign policy.

President Donald Trump, who pledged to wind down US involvement in conflicts around the world during his 2024 presidential campaign, has previously slammed Massie over his opposition to the war on Iran and efforts to force the government to release the Epstein Files.

Massie lost his primary election in May to a Trump-backed challenger and a barrage of spending by pro-Israel groups.