In an unprecedented move, US President Donald Trump is exploring the possibility of revoking the security clearance of nearly half a dozen former top national security officials who have been highly critical of his policies.

These officials are former CIA Director John Brennan, former FBI Director James Comey, former director of National Intelligence James Clapper, former director of the National Security Agency Michael Hayden, former National Security Adviser and UN Ambassador Susan Rice and former FBI Deputy Director Andrew McCabe.

The president is exploring the mechanisms to remove security clearance because they politicise and in some cases monetise their public service and security clearances, White House Press Secretary Sarah Sanders told reporters at her daily news conference.

Making baseless accusations of improper contact with Russia or being influenced by Russia against the president is extremely inappropriate, and the fact that people with security clearances are making these baseless charges provides inappropriate legitimacy to accusations with zero evidence, Sanders said.

However, she refused to give a time line for revoking the security clearance.

When we have further updates on that front, I’ll certainly let you know, she said.

Every speech he doesn’t like and he wants to punish them for it? she was asked. No, I think you are creating your own story there. The President doesn’t like the fact that people are politicising agencies and departments that are specifically meant to not be political and not meant to be monetised off of security clearances, the presidential spokesperson said.

When you have the highest level of security clearance, when you’re the person that holds the nation’s deepest, most sacred secrets at your hands and you go out and you make false accusations against the President of the United States, he thinks that is something to be very concerned with and we’re exploring what those options are and what that looks like, Sanders said.

Clapper described this as revengeful. This is kind of a petty way of retribution, I suppose for speaking out against the president, he told the CNN.

Hayden said that this would have no impact on what he says. I don’t go back for classified briefings. Won’t have any effect on what I say or write, he said on Twitter.

Following the president’s summit last week with Russia’s Vladimir Putin, Brennan, who headed the CIA under President Barack Obama, described Trump’s behavior as “nothing short of treasonous.” Comey was fired by Trump in May 2017.