SEIU Illinois State Council is dropping another $500,000 into Toni Preckwinkle’s mayoral campaign as she struggles to recoup from being dragged into the federal corruption scandal that threatens to bring down Ald. Edward Burke (14th).

The new money brings the union’s contribution to Preckwinkle to $1.5 million with more money on the way.

Four years ago, SEIU and its affiliates around the country contributed $3.5 million to Jesus “Chuy” Garcia’s 2015 campaign that forced Mayor Rahm Emanuel into a runoff but came up short.

Jerry Morrison, assistant to the president of SEIU Local 1, said the $500,000 contribution to Preckwinkle’s campaign was decided long before a criminal complaint accused Burke of muscling a $10,000 contribution to Preckwinkle’s re-election campaign for County Board president from a Burger King franchise owner whom Burke also allegedly shook down for legal business.

“Not at all. This was part of our schedule. We’ve given $1 million previously. This is another half-million dollars that had been approved by our board a month ago. We were authorized to give it when appropriate,” Morrison said Tuesday.

“It has nothing to do with anything going on out there. It has to do with the schedule we put ourselves on. This is what we were planning to do from the beginning. We’re fully committed to this race. Toni’s the best person to be mayor of Chicago. That’s why we’ve made the kind of financial commitment and commitment of people to the campaign.”

Preckwinkle’s campaign has been scrambling for nearly a week to explain why the $10,000 campaign contribution that Burke (14th) allegedly strong-armed from Burger King franchise owner was publicly reported only after the feds lowered the boom on Chicago’s most powerful and longest-serving alderman.

Preckwinkle aides also struggled to explain why their version of how the campaign handled the $10,000 that Burke allegedly pressured fast-food kingpin Shoukat Dhanani to donate as part of a fundraiser Burke hosted at his home for Preckwinkle’s re-election still does not jibe with the government’s account of the transaction.

The federal complaint says Dhanani — whose fast-food empire touts itself as the second-largest Burger King franchisee in the world — made a $10,000 donation to Preckwinkle at Burke’s request and that “correspondence provided by (Dhanani) and Individual B reflects that the committee confirmed the contribution was made.”

Preckwinkle’s committee never reported any donation from Dhanani until Jan. 3, 2019, the day the criminal charges were announced against Burke. This appears to be a violation of state election laws.

Hours later, Preckwinkle’s campaign staff filed new documents showing they received $10,000 from Dhanani on Jan. 12, 2018, and then immediately returned the entire $10,000 because the state election laws capped donations at $5,600.

Contrary to the criminal complaint, Preckwinkle’s campaign has produced screenshots that show she did return the entire $10,000 donation. She did not keep the legal limit of $5,600, while returning the excess contribution of $4,400, as the feds claim.

On Tuesday, Morrison was asked whether he believes Preckwinkle’s mayoral bid will survive the Burke scandal.

“I don’t have any reason to believe that the Burke thing has done any more harm to us than it has to anyone else,” he said.

“Ed Burke has raised money for over a hundred politicians in the state — including Susana Mendoza, [who has called Burke] her political mentor.”

Also on Tuesday, SEIU Local 1 released a digital ad that accuses Mendoza of “selling out” striking Chicago window washers last summer. The campaign could be a prelude to a larger campaign on commercial television, according to SEIU Local 1 spokesman Nick Desideri.

When the window washers asked Mendoza for help, she told them their demand for a $26-an-hour wage was too high, according to Desideri.

Instead, she sided with her “buddy and major campaign donor” Neal Zucker, CEO of Corporate Cleaning Services.

Zucker, whose company employed the window washers, has contributed more than $30,000 to Mendoza since 2014. That includes a $10,000 contribution shortly after the strike was settled.

Mendoza’s campaign issued a statement Tuesday night about the $25,000 digital buy, which features one of the striking window washers.

“This ad is another blatant lie by Toni Preckwinkle and her allies. Susana fought for higher wages for hard-working window washers,” Mendoza spokesman Christian Slater said in the statement. “What is true is this is classic pay to play politics from Toni Preckwinkle. Just like she gave Ed Burke Jr. a government job in exchange for $116,000 in donations, including $10,000 from the Ed Burke extortion scheme, Preckwinkle gave a big chunk of the $700 million in new county spending to hospital operations run in part by SEIU members in return for this $1.5 million payoff,” the statement said.

SEIU Local 1 is among a coalition of unions that owns the Chicago Sun-Times.