Internal Affairs should wash his mouth out with soap.

A police-union delegate trying to fix a speeding ticket was caught on a wiretap slamming NYPD Highway cops as a bunch of “a–holes” and “d—heads.”

Jaime Payan was explaining to Officer Julissa Goris that it could be time-consuming to take care of the infraction for her boyfriend’s cousin because Highway cops are sticklers for the rules.

“One thing that I know about these Highway dudes is that they’re all pretty much a–holes, you know what I’m saying?” Payan said during the eight-minute call on April 30 of last year.

“They’re all d—heads.”

The transcript emerged as part of former Bronx prosecutor Stephen Lopresti’s attempts to get a DWI bust dismissed because Goris was the arresting officer. Lopresti’s case is pending.

The conversation starts with some small talk, and then Goris tells Payan about the ticket and asks “if there was anything you can do.”

Goris says the ticket was issued earlier that day in Queens to a driver she later ID’d as George Aviles, and Payan tells her how he’ll proceed.

“I’ll just get the information from you and then I’ll get this taken care of. Worst-case scenario . . . he’ll have to plead not guilty and we’ll speak to the officer and then fix it before trial, OK?” Payan said. “But I’m obviously try[ing] to get it fixed before then.”

“All right,” Goris replies, according to the transcript, which IDs her as “Jennifer” instead of by her real name.

It’s unclear why she is misidentified.

During the call, the two cops gossip, banter about real-estate deals and gripe about broken cellphones like a couple of old pals at happy hour.

At one point, Goris can’t read the name of the cop who wrote the ticket, but Payan guesses it’s a Highway cop — and warns that could be a problem because they’re “different from regular cops.”

He then unleashes the profanity-laced description of the asphalt enforcers and explains their tickets take longer to eliminate.

“They have to show all their activity . . . but the majority of these summonses are fixed” before they go to court, Payan said.

Goris says that’s what happened when her mother was given a ticket — which also disappeared after the union intervened.

As the conversation winds down, Payan assures a relieved Goris the ticket will go away.

“I’m about to call the delegate from Highway . . . I’ll definitely take care of it,” he said.

“All righty, no problem. Thanks, Jaime,” Goris replies.

NYPD Internal Affairs cops have taped at least 30 officers as part of the department’s probe into the growing scandal, which also involves cops allegedly accepting cash, liquor and other gifts and trying to fix drunken-driving and domestic-violence charges for fellow cops, police sources said.

The sources say as many as 40 cops could face criminal charges in cases being investigated by the Bronx DA’s Office, and up to 500 could face disciplinary action resulting from the Internal Affairs probe.