The former Republican House speaker Kevin McCarthy is predicting that Donald Trump’s nomination of Matt Gaetz as attorney general will be rejected by the Republican Senate next year.

“Gaetz won’t get confirmed, everybody knows that,” McCarthy said in an interview with Bloomberg Television on Thursday. Gaetz orchestrated the successful effort to oust McCarthy from his leadership role last year.

The comments come amid growing calls by both Democrats and Republicans for the House ethics committee to release its report into Gaetz, from their investigation looking into allegations he engaged in sexual misconduct, illicit drug use and other ethical breaches.

The House investigation in effect ended on Wednesday, after Gaetz announced that he would be resigning from Congress following the announcement that Trump would be nominating him to be US attorney general.

Picking Gaetz to be the nation’s chief law enforcement officer in the justice department sent shock waves through Washington DC and nationwide on Wednesday.

Lisa Murkowski, the Republican senator of Alaska, said that she didn’t think the nomination was “serious” and that she was “looking forward to the opportunity to consider somebody that is serious”.

The Republican congressman Max Miller of Ohio also told Axios that Gaetz had “a better shot at having dinner with Queen Elizabeth II than being confirmed by the Senate”.

On Thursday morning, Dick Durbin, the Democratic chair of the Senate judiciary committee, called on the House ethics committee to share and preserve its report on Gaetz.

“The sequence and timing of Mr Gaetz’s resignation from the House raises serious questions about the contents of the House ethics committee report” Durbin said. “We cannot allow this valuable information from a bipartisan investigation to be hidden from the American people.”

Durbin added that the information in the report could be relevant to Gaetz’s confirmation as the next US attorney general.

The Republican senator John Cornyn also joined calls for the House ethics committee to release their report on Gaetz on Thursday, saying that he “absolutely” wanted to review the report examining the allegations.

“I don’t want there to be any limitation at all on what the Senate could consider,” Cornyn told reporters, according to Reuters. When asked if that meant he wanted to see the ethics report, he replied: “Absolutely.”

Gaetz was also investigated by the justice department in a sex-trafficking case, though the department ultimately declined to bring charges last year.

Gaetz has insisted throughout both investigations that he was innocent of any wrongdoing.

One of the lawyers representing an alleged victim of Gaetz’s said in a statement that Gaetz’s “likely nomination as Attorney General is a perverse development in a truly dark series of events” adding: “We would support the House Ethics Committee immediately releasing their report. She was a high school student and there were witnesses.”

Though McCarthy is predicting that Gaetz will not get confirmed as attorney general, there is a mechanism by which Trump could technically bypass a Senate vote, and make a recess appointment, which is when a president can make an appointment without a vote in the Senate while the upper chamber is in recess. Past presidents have used this method, often as a way to circumvent political divides that would slow nominations.