Mayor Rahm Emanuel did the right thing for crime-fighting — and helped himself politically — by using an 11 percent pay raise over five years and the lure of a retroactive pay raise to make pre-election peace with the police union, aldermen said Thursday.

The mayor’s office announced the tentative agreement one day after the Chicago Sun-Times disclosed that Chicago Police officers would get the retroactive pay raise that Emanuel once threatened to deny them after seizing on a paperwork mistake made by their ousted union president.

Emanuel’s statement did not reveal the terms of the new contract or confirm what other City Hall sources did: that the deal includes the same 11 percent pay raise over five years awarded to Chicago firefighters. That includes retroactive pay raises of 2 percent effective on both July 1, 2012, and Jan. 1, 2013.

“We believe this is a fair and responsible agreement — respectful of the hard work performed by the men and women of the Chicago Police Department to keep our residents safe, and respectful of Chicago’s hard-working taxpayers,”  Emanuel was quoted as saying.

Mayoral allies argued that striking a deal with the last city union still working under an expired contract could pay huge political dividends for Emanuel and his prospects for solving the city’s pension crisis. It’s the final piece in a remarkable turnaround in his relationship with organized labor four years after union leaders were nearly united in opposition to Emanuel’s candidacy.

“The CTU is probably a very good example of some unhappy unrest” — and why it’s unwise to go into a re-election campaign having angered a large group of voters, said Ald. Danny Solis (25th), one of Emanuel’s staunchest City Council supporters.

“You might have some repercussions — negative repercussions. . . .  We have a tough political environment. Mayor Daley saw that before his decision to retire. That’s carried over into this election. It’s not easy being an incumbent. People are frustrated and tired. This is going to help. . . .  All union members have family members. They have friends. They have neighbors and they’ll talk to them. This is a strong . . . union town.”  

Not only did Emanuel help himself at a time when his poll numbers are in the tank. He also did the “right thing” for the never-ending fight against violent crime in Chicago, Solis said.

“Our police are very important to our city. And their being satisfied with a good contract . . . helps with morale.”

Retiring Northwest Side Ald. Tim Cullerton (38th) co-signed a City Council resolution urging the mayor to grant police officers back pay.

“They earned it. They deserve it. I’m certainly glad that the contract’s been settled and all of the past controversy” has been put to rest, said Cullerton, whose ward is home to scores of police officers.

“Just about every Council meeting I’m at, we bring police officers in here [who] put their life on the line. They did an outstanding job during the NATO [summit]. They prove day in and day out that they’re worth every cent that we pay ’em.”

Cullerton said he does not believe the mayor’s timing was political. Emanuel’s most prominent potential challengers strongly disagreed.

“He’s done three years worth of damage and now in six months, as he’s struggling for his political life, he’s trying to make amends,” said Chicago Teachers Union President Karen Lewis.

“Police are going to see through this and I don’t think it’s going to make any difference. Now, you’re gonna give us a contract when you could have don’t this two years ago? He should have given them their retro pay. But, he should never have waited all this time. That’s how this guy is. He wants to play hardball with everybody. Now, he needs something. Now, he wants to play nice guy with them.”

Both the Fraternal Order of Police and the Chicago Firefighters Union Local 2 endorsed mayoral challenger Gery Chico over Emanuel in 2011.

The best Emanuel can hope for is that they stay neutral this time.

But Lewis argued that it won’t matter.

“I know what their rank-and-file will do. They won’t vote for him. They don’t like him,” she said.

“What they’ve told me is they feel very demoralized. They don’t like the notion he’s trying to rely on technology to do what real human beings need to do. They like the overtime money, but they’d also like some time off. Most of them are working almost every day. There are not enough people on the street. They don’t like the idea that’s he’s brought in outsiders and not moved people up through the ranks.”

Ald. Bob Fioretti (2nd) said he, too, believes police officers were “entitled” to back pay.

But, he said, “No mayor should have held that over anybody’s head. It was unfair to the men and women in blue who are on the front lines for us.”

Fioretti agreed with Lewis in arguing that Emanuel’s motives are political. He accused Emanuel of presiding over a scripted administration that’s “run by press releases and polling.”

“In the last few weeks — and in the next six months — he’s gonna do everything he can to try and win back the groups he has alienated,” the alderman said.

“It’s too little too late. It may satisfy them in terms of benefits, but will it satisfy them in terms of voting? That’s a different question. I hope they’re not used as political pawns.”

FOP President Dean Angelo was tied up in federal mediation and could not be reached for comment on the contract. He refused to reveal details in a text message to the Sun-Times.

“Too soon to get into any specifics. We must go to committee, board and reps before we share details,” he wrote. Union reps are expected to be briefed on the contract on Friday.

Last year, now-ousted FOP President Mike Shields apologized to his members for paperwork mistakes that denied rank-and-file Chicago Police officers their automatic right to a retroactive pay raise.

Shields’ oversight was in failing to notify the city between Feb. 1 and March 1 of 2012 that he intended to terminate the police contract and commence negotiations on a new agreement. If that notice is not given within the one-month window, the contract automatically rolls over for another year.

The mistake gave Emanuel an opening to declare that, if the FOP wanted a pay raise retroactive to June 30, 2012, they would have to give up something to get it. It would no longer be automatic.

The move was widely viewed as the mayor’s attempt to get even with Shields for working to torpedo a four-year contract with police sergeants — tied to pension and retiree health care reform — that Emanuel had hoped to use a road map to solve the city’s pension crisis.

Shields was subsequently removed from office after making the explosive charge that the last two police contracts dictated by an independent arbitrator were “fixed” in the city’s favor and that the recent sergeants contract arbitration may also have been rigged. He has blamed attorneys for the oversights.

When Angelo was elected to replace Shields, he set out to chart a new course with Emanuel and urged the mayor to put a retroactive pay back on the table as a show of good faith that could set the stage to solve the city’s pension crisis.