WASHINGTON — President Trump’s ex-lawyer Michael Cohen has “corroborating evidence for everything” he has told investigators, his former attorney Lanny Davis revealed Sunday on “Face the Nation.”

Davis, who is now just an adviser to Cohen, went on television as the president’s attorney Rudy Giuliani was doing the same — and labeling Cohen a liar.

Trump had taken to Twitter too, calling his ex-lawyer a “rat.” “They BROKE INTO AN ATTORNEY’s OFFICE!” Trump tweeted in all caps. “Why didn’t they break into the DNC to get the Server, or Crooked’s office?” he added, referring to the nickname he bestowed upon his former political rival, Hillary Clinton.

“This is the top law enforcement office in our system of government calling somebody who decides to tell the government the truth a ‘rat,’” Davis told CBS’ Margaret Brennan. “That’s the language of a mobster, not of the president.”

Davis also pointed out that when the FBI raided Cohen’s office and hotel room, they did so with a proper warrant.

“He not only consented to, he thanked them for their courtesy as they left,” Davis said, detailing Cohen’s interactions with agents. “And you have the president denouncing the FBI, lying about a warrant in a legal search, and he’s the top law enforcement officer of the country and who does he praise? He praises his people who have lied and refused to cooperate. The opposite of what a president should do.”

Davis said Cohen took ownership of his lies and his misdeeds.

“And he’s going to jail as a consequence and he authorized me, several times, to say he wouldn’t take a pardon from Donald Trump if it was handed to him,” Davis added.

Davis said a pardon was never discussed.

“And let’s remember that Michael Cohen has corroborating evidence for everything that he has said,” Davis noted.

Brennan asked if Cohen had evidence that linked Trump to Russia.

Davis replied that he couldn’t get in front of special counsel Robert Mueller’s findings, but pointed out how Cohen had provided information about the Moscow Trump Tower project and that he had been in contact with senior Russian officials.

“So there’s a lot in the Mueller memo that tells you how forthcoming, for 70 hours in seven meetings, Michael Cohen was with Mr. Mueller,” Davis explained.

Davis also said people at the White House knew that Cohen was going to initially lie about the Moscow Trump Tower project — and nobody pressed him to tell the truth. “Not one person from the White House, I can tell you this, ever said, ‘Don’t lie,’” Davis said.

Davis said Cohen decided to come clean because he “underwent a genuine transformation because he feared for his country and his family when Donald Trump was president.”