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Mayor de Blasio's opponents ripped him as corrupt and called for pay-to-play investigations to be reopened Friday, a day after explosive testimony from a donor who said his cash translated into access and favors from Hizzoner.

"Is that what we want in a mayor?" Republican Nicole Malliotakis asked in a phone interview with The News.

"Someone who is looking for the little loophole or the way to skirt ethics laws to get away with something that's inappropriate? To get away with violating the law? New Yorkers deserve better."

The testimony from Jona Rechnitz, a federal cooperating witness, came during the trial of former corrections union boss Norman Seabrook — one of several law enforcement figures he says he showered with cash in exchange for favors.

Rechnitz is at the center of an investigation into police corruption, but he testified Thursday that he'd also spread the love to the mayor — explicitly telling his top fund-raiser Ross Offinger that he'd bring in thousands, but would expect to get his calls answered and his favors done in return.

At an event Friday in Sunset Park, Brooklyn, de Blasio refused to answer questions about his relationship with Rechnitz, Rechnitz's testimony or whether he was corrupt, and ignored reporters — including one who asked "What's your price?" — as he walked away.

The mayor's relationship with Rechnitz and another donor involved in the scandal, Jeremy Reichberg, was probed by both the U.S. Attorney's office and District Attorney Cy Vance. Neither brought charges, but issued scathing statements saying the mayor had violated the spirit of campaign finance laws.

Malliotakis said that investigation needs to be reopened in light of Thursday's explicit testimony, but also because of donations the mayor's lawyers had made to District Attorney Cy Vance, who has been under pressure for taking contributions from defense attorneys.

Independent candidate and former detective Bo Dietl went further — dangling a pair of handcuffs as he stood outside the U.S. Attorney's office.

"I'm a former detective. You know what, I know one thing. You see these handcuffs?… These handcuffs should be put on our mayor," Dietl fumed. "I think I heard enough yesterday."

De Blasio spokesman Eric Phillips had mocked Rechnitz's credibility on Thursday, saying several agencies had investigated his claims and chosen not to charge anyone. He doubled down on Friday.

"If Jona Rechnitz says he bought the mayor, he is a liar. If he says he had unfettered access, he is a liar. The only thing Jona Rechnitz can say honestly is that he is a failed fixer of grand delusion just trying to save his own skin," Phillips said, insisting again the allegations were "re-heated, re-packaged" and that the administration did not make decisions based on contributions.

But Dietl argued the witness was trustworthy enough to the prosecution.

"This is a federal witness that is most credible to our U.S. attorney as a federal witness that he's telling the truth," Dietl said. "And I think the truth was spoken yesterday and it will continue at the trial."

Both candidates sought to use the blow to de Blasio as fodder for their own campaigns to take his job on Nov. 7.

"This is an opportunity for the people of New York to get decent representatives in City Hall," Malliotakis said. "Nov. 7 is an election and people who are unhappy with pay-to-play and corruption …. have to come out to vote."

Dietl said he'd been offered a bribe after "a guy killed a guy" in 1978, but instead wore a wire and arrested the person on bribery charges. He said this was de Blasio's "Hillary Clinton moment," referring to the release of a letter from FBI James Comey about her emails just weeks before the election that many believed turned the tide against her.

And he said the mayor was setting a bad example for children.

"Our kids, our young kids are reading these papers today and saying this is what I'm going to be when I grow up. I'm gonna be a corrupt guy, just like this mayor," Dietl said.