President Trump’s personal lawyer Rudy Giuliani said there is collusion going on — by special counsel Robert Mueller — and it’s “going to blow up on them.”

“The reality is, the real story is not that this case isn’t going to fizzle,” Giuliani said in an interview Wednesday night with Fox News’ Sean Hannity. “It’s going to blow up on them. The real question is, what we talked about before, there’s a lot more to what they did that nobody knows about yet.”

The former New York City mayor said Mueller’s investigation is “illegitimate” and questioned why the special counsel wasn’t delving into the dossier compiled by former British intelligence officer Christopher Steele that contained unsubstantiated but salacious details about Trump.

“Can it get any worse? I mean, what do we need to know that this is a totally illegitimate investigation based on a report, a dossier that was paid for by Hillary Clinton and the Democrats — probably the biggest illegality so far, the biggest collusion so far,” Giuliani told Hannity.

“Completely made up. Completely made up. Led to nothing except several fraudulent FISA wires,” he added.

Giuliani then suggested that Mueller switch gears in his probe and look into Clinton.

“Well, maybe if Mueller and his band of whatever they are, Democrats, right, were fair-minded, maybe they’d investigate — maybe that’s the collusion. Maybe that’s the collusion,” he said, referring to the dossier.

Giuliani and Trump’s legal team, who have been negotiating with Mueller over interviewing the president, on Wednesday said they responded to the special counsel’s latest request and called for the probe to wrap up by Sept. 1 — well before the November midterm elections.

He told Hannity that if Mueller doesn’t finish by that date, “then we have a very, very serious violation of the Justice Department rules that you shouldn’t be conducting one of these investigations in the 60-day period.”

Giuliani also repeated his claim that Mueller wants to interview Trump so that he can get him on a perjury charge.

“Hey, Bob, you know it. Why do you want to get him under oath? Do you think we’re fools?,” Giuliani said. “You want to get him under oath because you want to trap him into perjury. Well, we’re not going to let you do that.”

Giuliani also said any questions about possible obstruction should be off limits to Mueller’s prosecutors during an interview.

“The reality is he doesn’t need to ask a single question on obstruction, he has all the answers. They are not going to change.

“The president is not going to change his testimony,” Giuliani said.