WASHINGTON – President Trump’s transition team plans to request back “many tens of thousands” of emails from Special Counsel Robert Mue​ller they believe were unlawfully obtained during the ongoing probe​ of Russian involvement in the 2016 election​, according to a new report Sunday.

The transition team, which operated between Trump’s election and his inauguration, will send a letter to Mueller claiming some emails were “privileged” communications, and need to be returned, according to an Axios report.

“It’s not looking good,” Trump said of how Mueller obtained a cache of emails from his transition team. “It’s quite sad to see that. My people are very upset about it. I can’t imagine there’s anything on ‘em, frankly, because as we said, there’s no collusion.”

The desire to claw back thousands of documents follows a letter sent Saturday to the House and Senate from a lawyer representing the Trump Transition team alleging that career staff at the General Services Administration “unlawfully” provided private transition team emails to Mueller, despite not owning the records in question or vetting them for privileged communications.

Mueller has made “extensive use” of the materials in his ongoing criminal probe, according to the letter penned by Kory Langhofer, Counsel to Trump for America, Inc.

But a spokesman for Mueller’s office stood by the way the special counsel obtained the documents.

“When we have obtained emails in the course of our ongoing criminal investigation, we have secured either the account owner’s consent or appropriate criminal process,” said spokesman Peter Carr.

Trump’s backers have worked to discredit the Mueller probe, which has resulted in four indictments. Fueling the fire are private text messages from a top FBI official Peter Strzok that blast Trump. Once the Trump hatred was discovered, Mueller removed Strzok.

A Trump transition team official told the Post Sunday they have not yet made the request to Mueller’s office for the documents. Trump said Sunday he has “no” intention of firing Mueller.

Criminal defense Attorney Philip A. Holloway said potential future defendants in the Mueller probe could make a fruit of the poisonous tree argument in court. If a judge decides the emails were illegally obtained, then any further evidence gained from the illegal seizure would be tainted and excluded in court.

“While this ultimately may be an issue for a judge to decide, it could easily run the special counsel’s investigation off the tracks,” Holloway told The Post.

Meanwhile, it can be viewed as “incompetence or overzealousness” by Mueller and fodder for the Special Counsel’s ouster.

“One has to believe that President Trump would love nothing more than to have a solid basis to fire Mueller,” Holloway said.

Another attorney Ron Koby chalked up the Trump transition team accusations as fuel for right-wing political pressure to fire Mueller, but a “flimsy” legal argument in court.

“There’s enough there for a defense lawyer to complain about, but not enough there for a defense lawyer to prevail,” Koby told The Post.

Meanwhile, the Trump Transition team is asking for a legislative fix to prevent future transition documents from being improperly commandeered.

A spokesperson for Rep. Trey Gowdy at the House Oversight Committee said the legal issues raised by the Team Trump are best decided by courts, not Congress. But the committee will take the team’s suggestions on fixing the laws “under advisement.”