FORMER US security officials have issued scathing rebukes to Donald Trump for withdrawing a former spy chief’s security clearance in what they cast as an act of political vengeance.

The president insisted he had to do “something” about the “rigged” federal probe of Russian election interference.

His admission that he acted out of frustration about the Russia probe underscored his willingness to use his executive power to fight back against an investigation he sees as a threat to his presidency.

Legal experts said the dispute may add to the evidence being reviewed by special counsel Robert Mueller.

In an opinion piece in the New York Times, former CIA director John Brennan said Trump’s decision to deny him access to classified information was a desperate attempt to end Mueller’s investigation.

Brennan, who served under Barack Obama and has become a vocal Trump critic, called the president’s claims that he did not collude with Russia “hogwash”.

The only question remaining is whether the collusion amounts to a “constituted criminally liable conspiracy”, Brennan wrote.

Later, the retired navy admiral who oversaw the raid that killed Osama bin Laden called Trump’s moves “McCarthy-era tactics”.

William H McRaven said he would “consider it an honour” if Trump would revoke his clearance as well.

“Through your actions, you have embarrassed us in the eyes of our children, humiliated us on the world stage and, worst of all, divided us as a nation,” McRaven wrote.

That was followed by a joint letter from 12 former senior intelligence officials calling Trump’s action “ill-considered and unprecedented”.

They said it “has nothing to do with who should and should not hold security clearances – and everything to do with an attempt to stifle free speech”.

The signatories included six former CIA directors, five former deputy directors and former director of national intelligence James Clapper.

Two of the signatories – Clapper and former CIA director Michael Hayden – have appeared on a White House list of people who may also have their security clearances revoked.