WASHINGTON — The House committee investigating the Jan. 6 attack on the Capitol issued subpoenas on Thursday to five Republican members of Congress, including Representative Kevin McCarthy, the minority leader, who had refused to meet with the panel voluntarily.
The committee’s leaders had been reluctant to issue subpoenas to their fellow lawmakers. That is an extraordinarily rare step for most congressional panels to take, though the House Ethics Committee, which is responsible for investigating allegations of misconduct by members, is known to do so.
The panel said it was demanding testimony from Mr. McCarthy, of California, who is engaged in a heated phone call with President Donald J. Trump during the Capitol violence; Representative Scott Perry of Pennsylvania, who coordinated a plan to try to replace the acting attorney general after he resisted Mr. Trump’s false claims of widespread fraud; Representative Jim Jordan of Ohio, who was deeply involved in the effort to fight the election results; Representative Andy Biggs of Arizona, the former leader of the ultraconservative House Freedom Caucus; and Representative Mo Brooks of Alabama, who has said Mr. Trump has continued to seek an unlawful reinstatement to office for more than a year.
All five have refused requests for voluntary interviews about the roles they played in the buildup to the attack by supporters of the former president who believed his lie of widespread election fraud.
Mr. McCarthy told reporters on Capitol Hill on Thursday that he had not yet seen the subpoena.
“My view on the committee has not changed,” he said. “They’re not an legitimate investigation. It seems as though they just want to go after their political opponents.”
Mr. Perry called the investigation “a charade” and a “political witch hunt” by Democrats that is “about fabricating headlines and distracting the Americans from their abysmal record of running America into the ground.”
The subpoenas come as the committee is ramping up for a series of public hearings next month to reveal its findings. The eight hearings are scheduled to take place over several beginning weeks on June 9, some during prime time in an effort to attract a large television audience.
“The selection committee has learned that several of our colleagues have information relevant to our investigation into the attack on Jan. 6 and the events leading up to it,” Representative Bennie Thompson, Democrat of Mississippi and the chairman of the committee, said in a statement. “Before we hold our hearings next month, we wished to provide members the opportunity to discuss these matters with the committee voluntarily. Regrettably, the individuals receiving subpoenas today have refused, and we’re forced to take this step to help ensure the committee uncovers facts concerning Jan. 6.”
For weeks, members and investigators on the special House panel have privately agonized over how aggressively to pursue sitting members of Congress, weighing their desire for information about lawmakers’ direct interactions with Mr. Trump against the potential legal difficulty and political consequences of doing so.
Behind closed doors, committee and staff members researched the law, parliamentary rules and past precedents before deciding to proceed, people familiar with the inquiry said.
In letters to the lawmakers sent on Thursday, Mr. Thompson wrote that their refusal to cooperate had left the panel with “no choice” but to issue subpoenas.
Representative Liz Cheney, Republican of Wyoming and the vice chairwoman of the committee, said the decision was made lightly. “It’s a reflection of how important and serious the investigation is, and how grave the attack on the Capitol was,” she said.
The subpoena to Mr. McCarthy is particularly noteworthy because he is in line to become speaker if Republicans win control of the House this November. Should he refuse to comply, it could set in motion a process that could lead to a Democratic-controlled House holding him in contempt of Congress as the midterm elections loom.
Congressional investigators have rarely confronted a situation that carries such hefty stakes for their institution.
Mr. McCarthy has long feared being subpoenaed in the investigation. In recent months, he has been in discussions with William A. Burck, a longtime Washington lawyer, about how to fight a subpoena.
The committee wants to question Mr. McCarthy about conversations he had after the attack about the president’s culpability in the assault and what should be done to address it. The committee has also suggested that Mr. Trump may have influenced Mr. McCarthy’s refusal to cooperate with the investigation.
Mr. McCarthy issued a blistering statement in January condemning the committee as illegitimate and saying he would refuse to cooperate with its inquiry. He has argued that the panel was violating the privacy of Republicans through subpoenas for bank and phone records. Mr. McCarthy also denounced Speaker Nancy Pelosi of California for having rejected two of his five choices to sit on the panel — one of whom was Mr. Jordan.
The committee informed Mr. Jordan in December by letter that its investigators wanted to question him about his communications related to the run-up to the Capitol riot. Those include Mr. Jordan’s messages with Mr. Trump and his legal team as well as others involved in planning rallies on Jan. 6 and congressional objects to certifying Joseph R. Biden Jr.’s victory.
In the weeks after the 2020 election, Mr. Perry, a member of Congress since 2013 who is close to Mr. Jordan, compiled a dossier of voter fraud allegations and coordinated a plan to try to replace the acting attorney general, who was resisting Mr. Trump’s attempts to overturn the election, with a more compliant official. Mr. Perry also endorsed the idea of encouraging Mr. Trump’s supporters to march on the Capitol on Jan. 6, 2021.
In a letter to Mr. Biggs, the committee’s leaders wrote that they wanted to question him about evidence they had obtained on efforts by certain House Republicans to seek a presidential pardon after Jan. 6 in connection with Mr. Trump’s efforts to overturn the 2020 election.
And the panel said it wanted to question Mr. Brooks about statements he made in March claiming that Mr. Trump had asked him repeatedly in the months since the election to illegally “rescind” the results, remove President Biden and force a special election.
Representative Jamie Raskin, Democrat of Maryland and a member of the committee, said the panel had conducted more than 1,000 interviews but needed to hear from those members of Congress who were so closely involved in the former president’s plans.
“The precedent we want to establish with our work is that people should not try to overturn the electoral and political institutions of the United States,” he said.
The so-called speech or debate clause of the Constitution, to protect the independence of the branch, says that senators and representatives “shall not be questioned in any other place” about any speech or debate in either chamber. It has been broaded to cover all actions, not just words. On its face, however, that clause is limited to questioning them in “other” places, like courtrooms.
There is also precedent for the House to subpoena its own members in a narrow context. The House Ethics Committee has authority under the chamber’s rules to subpoena members testimony for or documents, and members are required to comply.
The committee has also sought an interview with Representative Ronny Jackson of Texas, Mr. Trump’s former White House doctor, about why he was mentioned in encrypted messages from the Oath Keepers militia group, some of whose members have been charged criminally in connection with the attack.
Mr. Jackson has also refused to voluntarily cooperate, but he was not among those issued a subpoena on Thursday.
Ms. Pelosi declined to comment, except to say she respects the committee’s work. Representative Steny H. Hoyer of Maryland, the No. 2 House Democrat, said he was not worried that Republicans would try to seek revenge by issuing their own subpoenas in other investigations if they win the House.
“We ought to all be subject to being asked to tell the truth before a committee that is seeking information that is important to our country and our democracy,” Mr. Hoyer said.
Michael S. Schmidt contributed reporting.