The former CIA director John Brennan

Donald Trump continued on Saturday to broadcast caustic criticism of former CIA director John Brennan, three days after stripping him of his security clearance.

Trump tweeted on Saturday morning:  “Has anyone looked at the mistakes that John Brennan made while serving as CIA director?  He will go down as easily the WORST in history & since getting out, he has become nothing less than a loudmouth, partisan, political hack who cannot be trusted with the secrets to our country!”

Trump’s comments, certain to escalate tension between the White House and the US  intelligence community that already borders on open hostility, appeared to have been made in reaction to an interview Brennan gave MSNBC on Friday.

In that interview Brennan accused Trump of being drunk on power.  He said: “I think is just so reflective of somebody who, quite frankly, I don’t want to use this term maybe, but he’s drunk on power. He really is, and I think he’s abusing the powers of that office.”

The president’s developing policy of using the withdrawal of security clearance as a sign of disapproval or punishment is causing alarm in Washington.

Even some presidential aides in the White House are saying "the threatened revocations smack of a Nixonian enemies list, with little or no substantive national security justification".

Democrats, and some Republicans, denounced the president’s move, with the leading Democrat Nancy Pelosi calling it a “stunning abuse of power”.

In his MSNBC interview,  Brennan referred to Trumps actions against him and said: “This is not going to deter me at all. I am still going to speak out.” He described it as an effort “to cow individuals inside and outside the US government” and compared it to behavior from “foreign tyrants and despots”.

 Brennan  also called Donald Trump’s repeated denials that his campaign colluded with Russia during the 2016 election “hogwash” and accused the president of revoking his security clearance as part of a “desperate” attempt to interfere with the special counsel’s investigation.