The detectives and captains’ unions had endorsed Mark Weprin’s re-election bid.

Had is the operative word here.

That was before he voted for the community safety act. And it was before he got a new opponent: former cop Joe Concannon.

“The question I have for Councilman Mark Weprin… is why does Weprin lie?” asked Michael Palladino, the head of the detectives union, on the steps of City Hall this afternoon. “He told us he would not support it… He gained our endorsement under false pretences.”

He summed up his thoughts like this: “He is more concerned about bettering his political career than his constituents.”

Both the captains’ union and the detectives’ union backed Concannon today instead, tossing out whatever support they had of Weprin. They were joined by the PBA and the Lieutenants Benevolent Association.

 Concannon does not support the community safety act, which would create an independent inspector general to oversee the NYPD. It also allows New Yorkers to sue for biased-based profiling in state court.

“I can assure you I will never risk the safety and the security of one New York City citizen at any time at all — no matter who comes to my desk and no matter who tries to pander to get into higher elected office,” Concannon said.

Concannon and several union officials accused Weprin of voting for the community safety act  to win over votes for a potential run for speaker.

We caught up with Weprin this afternoon to chat about all of this. Here is what he said:

Not everyone agrees on every issue. You are always going to have issues that people don’t agree with how you vote. But I work very hard on behalf of my constituents. And I think they know that… this is an issue where I think the stop and frisk policy needs to be reformed.

He said the unions’ arguments are unsubstantiated. And he also wouldn’t bite when it comes to his pursuit of the speakership. He said he would answer those questions after the general election.

Concannon was thought to have been courted by the Bloomberg administration to run for City Council — part of the mayor’s attack on the community safety act. When asked about that on Thursday, Concannon said this:

A: I have been speaking to Mayor Bloomberg for a number of years since I have been seeking political office. The Bloomberg administration and my campaign are lockstep as far as this issue is concerned. Other than that we are not going to discuss campaign strategy.”

Q: Did he ask you to run?

A: I am not going to get into campaign strategy.

Q: But you were talking to him?

A: We’ve been talking to a lot of people.

Concannon is running on the “reform” party line. He is in the process of collecting petitions.