WASHINGTON — House investigators issued subpoenas on Thursday to compel two associates of Rudolph W. Giuliani to sit for depositions in the impeachment inquiry, just hours after the men were indicted on campaign finance charges that touched on their work in Ukraine.
Three chairmen leading the investigation of President Trump’s efforts to pressure Ukraine to investigate his political rivals wrote that the associates, Lev Parnas and Igor Fruman, were required to appear for a deposition next Wednesday and hand over records related to their work with Mr. Giuliani, Mr. Trump’s private lawyer.
Mr. Giuliani was at the center of Mr. Trump’s attempts to persuade the Ukrainian government to open corruption investigations into former Vice President Joseph R. Biden Jr. and his son, and other Democrats, efforts that are now the subject of a rapidly expanding impeachment inquiry.
The House investigation has touched off a constitutional clash, as the White House has signaled that it will stonewall all requests for witnesses and documents. The latest subpoenas emerged as criticism of the president’s actions in the Ukraine matter continued to grow. Asked whether it was proper for the president to solicit foreign interference in the political process, H.R. McMaster, Mr. Trump’s former national security adviser, responded, “Of course it is not appropriate.”
Speaking at an event in Washington on Thursday, Mr. McMaster said it was up to Congress “to make a judgment as to whether or not that happened.”
It was unclear how the indictment unsealed on Thursday morning would influence the impeachment inquiry. Mr. Parnas had been scheduled to appear for a deposition on Capitol Hill on Thursday and Mr. Fruman on Friday. But even before their arrests, their lawyer, John M. Dowd, had indicated that they would not comply voluntarily.
The subpoena issued by the House Intelligence Committee makes no mention of the federal indictment. The F.B.I. arrested the two men as they were about to board an international flight late Wednesday, and on Thursday federal prosecutors charged them with funneling foreign money to government officials and campaigns in an effort to influence American policy, including toward Ukraine.
In a letter to Mr. Dowd, the three House chairmen wrote that as private citizens, Mr. Parnas and Mr. Fruman were “required by law to comply with the enclosed subpoenas.” It was signed by Representative Adam B. Schiff, the chairman of the Intelligence Committee; Representative Elijah E. Cummings, the chairman of the Oversight and Reform Committee; and Representative Eliot L. Engel, the chairman of the Foreign Affairs Committee.
“They may not evade requests from Congress for documents and information necessary to conduct our inquiry,” the chairmen wrote. “They are not exempted from this requirement merely because they happen to work with Mr. Giuliani, and they may not defy congressional subpoenas merely because President Trump has chosen the path of denial, defiance and obstruction.”
The indictments could complicate congressional attempts to get them to testify, raising such issues as whether lawmakers will grant immunity to them that would bar the use of their testimony as criminal evidence.
Also, an assertion of Fifth Amendment rights against self-incrimination is a lawful basis to avoid answering questions despite a subpoena.
The New York Times reported in May that the two men helped connect Mr. Giuliani to Ukrainian prosecutors who provided him information related to the investigations he wanted into Mr. Biden and his son Hunter, as well as a debunked conspiracy about Ukrainian meddling to aid Democrats in the 2016 election.
The federal indictment in Manhattan made no mention of Mr. Giuliani, but stated that the men worked with one or more Ukrainian government official to try to secure the removal of Marie L. Yovanovitch as the United States’ ambassador to the country.
Mr. Giuliani was seeking Ms. Yovanovitch’s removal, as well, and ultimately the White House called her back to Washington early, having deemed her insufficiently loyal to the president.
House investigators are scheduled to hear from Ms. Yovanovitch on Friday in a private deposition, but as of midday Thursday, it remained unclear if the State Department would try to block her testimony. Democrats were prepared to issue a subpoena to increase pressure if needed.
The indictment may also significantly complicate Mr. Giuliani’s ability to serve as a face of the president’s defense. Senate Republicans allied with the president have said they might host a public hearing with Mr. Giuliani in an effort to showcase his accusations against the Bidens and undercut the House’s impeachment narrative. Now they may simply decide he is too toxic to expose to public questioning.
Charlie Savage and Peter Baker contributed reporting.