Senate Democrats have delayed a confirmation vote on Labor Secretary nominee Thomas Perez after Republicans threatened to use a separate hearing to criticize his handling of a whistleblower case.

A vote in the Senate Health, Education, Labor and Pensions Committee that had been set for Thursday has been pushed back to May 8.

Committee Chairman Tom Harkin (D-Iowa) said he was concerned that Republicans would use the separate hearing as a forum to attack Perez in his absence.

Harkin canceled the hearing on federal whistleblower laws, which also was scheduled for Thursday.

Republicans have criticized Perez for declining to intervene in a whistleblower case against St. Paul, Minn., while he headed the Justice Department’s Civil Rights Division. Perez made the decision as part of a deal in which the city of St. Paul agreed to withdraw another case from the Supreme Court that could have threatened the Justice Department’s strategy in bringing housing discrimination ­cases.

Labor Secretary nominee Thomas Perez testifies on Apr. 18 on Capitol Hill before the Senate Health, Education, Labor and Pensions Committee hearing on his nomination. (Molly Riley/AP)

Republicans claim that Perez made the deal based on political ideology and not the merits of the whistleblower case, which could have won nearly $200 million for taxpayers. Perez has said the deal was in the best interest of the nation and was made only after receiving approval from senior Justice Department officials.

Senate Republicans had asked Harkin this week to postpone the committee vote on Perez, saying they needed more time to examine the deal. Harkin had refused the request but later changed his mind.

The change of heart occurred after Republicans planned to have the plaintiff in the whistleblower case, Frederick Newell, testify at a hearing about weaknesses in whistleblower laws at the Occupational Safety and Health Administration.

“While I continue to believe there are no impediments to Mr. Perez’s confirmation, I am agreeing to postpone his committee vote until May 8, in order to allow those senators who have asked [for] the time to request additional information they believe they need and to evaluate his qualifications,” Harkin said.

The committee’s ranking Republican, Sen. Lamar Alexander (Tenn.), said the delay was appropriate “so that senators could get responses to a number of outstanding questions as we evaluate this nominee.”

— Associated Press