Members of the Senate Foreign Relations Committee are expected to clash Thursday over at least three of President Trump’s nominees to diplomatic and development posts because of questions related to their disclosure forms and FBI background checks, according to people familiar with the dispute.

Democrats on the panel have been urging the committee chairman, Sen. James E. Risch (R-Idaho), to postpone the confirmation hearing, seeking more time to vet the nominees whose cases have sparked concerns. But in a break from long-standing committee precedent, Risch elected to push forward with the hearing over Democrats’ objections.

The panel’s ranking Democrat, Sen. Robert Menendez (D-N.J.), has not agreed to move forward with confirmation hearings for Marshall Billingslea, the Treasury Department’s assistant secretary for terrorist financing, who has been nominated to serve as undersecretary of state for civilian security, democracy and human rights. He also did not agree to move forward with hearings for former California congressman Darrell Issa (R), whom Trump picked as the next director of the U.S. Trade and Development Agency.

Menendez did agree to proceed with a hearing for documentary producer and filmmaker Michael Pack’s bid to lead the Broadcasting Board of Governors, but recent concerns over Pack’s paperwork may throw his confirmation process into disarray.

The specific nature of the alleged problems with the paperwork for Billingslea, Issa and Pack have not been made public. The matter with Issa concerns an event from before his political career that was left off his committee disclosure form but that surfaced in his background check, according to people familiar with the documents.

On Wednesday, Risch dismissed those concerns as “much ado about nothing.”

A senior administration official with knowledge of the confirmation process, who spoke on the condition of anonymity to discuss internal deliberations, said Wednesday night that he was “confident that Mr. Issa disclosed everything that needed to be disclosed.”

The official added that the FBI cleared Issa and that panel members never raised such concerns with Issa directly.

Calls and emails to Pack and representatives for Billingslea were not returned Wednesday evening.

Democrats have been emphatic enough in their concerns that Risch asked the White House to make nominees’ background checks available to all panel members for their perusal before Thursday’s confirmation hearing. As of Wednesday night, the White House had not responded.

Even absent concerns about their disclosure forms, the confirmation process for Issa, Billingslea and Pack was expected to face partisan hurdles. Each was nominated at least a year ago, initially, but their bids have been pending as lawmakers argue about their fitness for the positions.

Issa, who as chairman of the House Oversight Committee went after the Barack Obama administration over matters such as an attack on a U.S. post in Benghazi, Libya, and the Justice Department’s “Fast and Furious” gun-tracking operation, launched an exploratory committee last month to challenge Rep. Duncan D. Hunter (R-Calif.) for his seat. Hunter was indicted last year on 60 criminal counts related to misuse of campaign funds.

Some members have expressed concern that if Issa has his eye on returning to Congress, he will not be committed to the job at the U.S. Trade and Development Agency. Issa, who was seen with the president Wednesday during a trip to California, has said he will run for office if he is not confirmed by Nov. 3.

Billingslea has been a politically polarizing figure because of the role he played running special operations in the Defense Department of the George W. Bush administration.

Human Rights Watch and several other groups have vociferously opposed his nomination over what they say is his “well-documented history of advocating for the use of torture and other unlawful interrogation practices” while at the Pentagon. Democrats on the Senate Foreign Relations Committee also are concerned that there may be outstanding documents pertaining to his time there that they have yet to view.

Spokespeople for the Pentagon did not respond to a request for comment Wednesday evening.

Pack’s ties to right-wing media have also fueled opposition to his nomination to serve as chief executive of the Broadcasting Board of Governors, the body that oversees Voice of America, Radio Free Europe and other U.S. government-funded media outlets. Pack’s critics have questioned whether his close relationship with former Trump campaign manager Stephen K. Bannon, in particular, means that he will turn those organizations into pro-Trump propaganda outfits.

The panel on Thursday will also consider the nomination of Adam Seth Boehler to lead the International Development Finance Corp. His bid has not inspired partisan divisions.

Mike DeBonis and Philip Rucker contributed to this report.