US President Donald Trump says his frustrations with the investigation into alleged Russian election meddling forced him to revoke the security clearance of ex-CIA chief John Brennan.
"It is a sham," he told the Wall Street Journal. Revoking Mr Brennan’s clearance "had to be done".
The White House had earlier said Mr Brennan’s access was revoked because of "erratic conduct".
The vocal critic of the president can no longer access sensitive information.
In response, Mr Brennan said the move was part of President Trump’s broader effort to "suppress freedom of speech and punish critics".
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Special Counsel Robert Mueller is looking into Russia’s alleged efforts to interfere in the 2016 US election, and whether there was any collusion between the Kremlin and Mr Trump’s campaign.
Mr Trump told the Wall Street Journal that "these people" – including Mr Brennan – had "led" the Russia inquiry.
The Russia probe is being led by the FBI, the US domestic intelligence service. Mr Brennan headed the CIA, the foreign intelligence service, when the alleged hacking took place and stepped down after Mr Trump won the election.
However there was no mention of the Russia inquiry in Mr Trump’s earlier statement announcing the decision to revoke Mr Brennan’s clearance.
It said Mr Brennan had made "outrageous allegations" against the administration.
John O. Brennan
This action is part of a broader effort by Mr. Trump to suppress freedom of speech & punish critics. It should gravely worry all Americans, including intelligence professionals, about the cost of speaking out. My principles are worth far more than clearances. I will not relent.
BREAKING: President Trump is revoking former CIA Director and high-profile Trump critic John Brennan’s security clearance, White House says.
Last year, Mr Brennan said the Russia inquiry was "well-founded" because Russians had "brazenly interfered" in the vote.
President Trump has repeatedly denied the claim, calling it a "witch hunt".
What did Trump’s statement say exactly?
Sarah Sanders read President Trump’s statement which cited John Brennan’s "erratic conduct and behaviour"
Mr Trump said that while former intelligence heads continued to have security access so they could advise their successors, "neither of these justifications supports Mr Brennan’s continued access to classified information".
The statement added that Mr Trump was also reviewing access to classified information for nine other high-ranking officials, all of whom have criticised the president.
These include former FBI chief James Comey, who was fired last year, former director of national intelligence James Clapper, former National Security Agency director Michael Hayden and former attorney general Sally Yates.
What has the reaction been?
Mr Brennan said in another tweet that the move "should gravely worry all Americans, including intelligence professionals, about the cost of speaking out."
"My principles are worth far more than clearances," he added." "I will not relent."
James Comey called the president "morally unfit" to lead. His memoir, A Higher Loyalty, likened Mr Trump to a mob boss.
He said in a statement: "Once again this president is sending a message that he will punish people who disagree with him and reward those who praise him."
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Mr Comey added that "security clearances should not be used as pawns in a petty political game to distract voters from even bigger problems".
Mr Trump is reviewing access for several other former high-ranking US officials
Some Republicans praised the move, including Senator Rand Paul who said he "urged the president to do this."
"[Mr Brennan's] behaviour in government and out of it demonstrate why he should not be allowed near classified information," he said in a statement.
Louisiana Senator John Kennedy said Mr Brennan had "been totally political" and had "given the national intelligence community a bad name."
"I don’t see why he would need a security clearance, I really don’t," he told CNN.