United States Republican Representative Thomas Massie has introduced a resolution to impeach US Defense Secretary Pete Hegseth over the war on Iran, strikes on purported drug boats and other alleged violations of US laws.

Reading from the text of the resolution in the House of Representatives on Monday, the outgoing Kentucky lawmaker accused Hegseth of carrying out unlawful orders and posing a threat to the Constitution.

Massie introduced the articles of impeachment as soon as the House opened for its first session after the midterm elections. Democratic Party leaders have pledged to investigate US President Donald Trump’s administration in Congress following their landslide victories in both chambers.

Massie reintroduced eight articles of impeachment against the defense secretary that he had first raised in September. Republican House Speaker Mike Johnson avoided a vote in the Republican-led Congress at the time by sending lawmakers home early.

In a news conference on Monday, Massie said he would welcome votes from any lawmakers who want Hegseth removed, even if they have not read the details of his bill.

“I understand that some of them just want to vote for this because they just want to see Hegseth gone,” he said. “I welcome their vote.”

He urged the defense secretary to resign before Democrats take control of Congress in January, predicting their investigations will include testimony from senior administration officials on how the Defense Department has been run under Hegseth.

Hegseth remained defiant, saying he welcomes the opportunity to defend his actions in Congress.

“There’s a lot of politically motivated people who may have substantial policy disagreements, but their disagreements are with success,” Hegseth told reporters on Monday. “If we want to litigate” the military actions that the Trump administration has taken, he added, “I’m happy to do it all day long.”

He is expected to hold a news conference on Tuesday.

Massie’s resolution alleges that Hegseth violated the Constitution by helping carry out the war on Iran without congressional authorisation, as mandated by the War Powers Resolution.

Hegseth “cultivated a warmaking culture” dismissive of rules of engagement that caused civilian harm, Massie alleges. He cited the US bombing of a school in Minab, Iran, which killed more than 150 people, including about 120 children, at the start of the US-Israel war in February.

The resolution also alleges that US strikes on alleged narcotics boats in the Caribbean and Pacific ignored mandatory safeguards and amounted to extrajudicial killings by Hegseth.

Other charges against Hegseth involve the abduction of former Venezuelan President Nicolas Maduro, suppressing free speech by restricting media access to the Pentagon and carrying out an unlawful war in Yemen against the Houthis.

Massie has been a frequent critic of Trump’s administration, particularly the Iran war. His outspoken nature has previously drawn anger from Trump, who backed a rival Republican candidate who defeated Massie in the primary elections earlier this year.

A majority of the 435-member House of Representatives would need to vote in favour of Hegseth’s impeachment. Two-thirds of the Senate’s 100 lawmakers would then need to vote to remove him.

While the measure is unlikely to succeed in the current Republican-led Congress, pressure is likely to mount on Hegseth when a new set of Democratic lawmakers, who won a sweeping victory in the midterm elections, are sworn into office in January.

House Minority Leader Hakeem Jeffries, who is expected to become speaker in January, said over the weekend that he supported Hegseth’s impeachment.

“The so-called secretary of defence has abused his power, undermined our national security, and engineered this reckless and costly war of choice in Iran,” Jeffries said.

Although Democrats will hold the majority in the Senate, they are expected to have about 54 seats in the upper chamber of Congress – short of the 67 votes needed to convict and remove Hegseth.

Massie is also attempting to impeach Hegseth despite the objections of his own Republican Party, including from key leaders like Johnson.

“We don’t impeach Cabinet secretaries for political gain or for cheap tricks, and I think that’s what this is, and I think everybody knows it,” Johnson told reporters.

Trump administration officials have baulked at any attempt to impeach Hegseth, while simultaneously acknowledging the deep unpopularity of the war on Iran, which some have admitted likely cost Republicans the midterm elections.

“He’s guilty of two things, basically winning two wars,” Trump said about Hegseth on Sunday. “I believe we saved the Middle East and Israel combined. And it’s awfully hard to say let’s impeach somebody who did that.”

Secretary of State Marco Rubio also defended Hegseth, saying he has “done a good job” despite widespread criticism. Rubio also called the Iran war “necessary” while acknowledging that it was not “necessarily popular”.