Washington (CNN) President Donald Trump is considering stripping a half-dozen former national security officials of their security clearances, White House press secretary Sarah Sanders said Monday, calling their public commentary about the ongoing Russia probe inappropriate.

Such a move would amount to an unprecedented use of presidential authority to punish political rivals. Critics quickly seized on the announcement, even as those under consideration downplayed the actual effect losing their clearances might have.

The list of former officials under consideration includes former CIA Director John Brennan, former Director of National Intelligence James Clapper, former FBI Director James Comey, former national security adviser Susan Rice, former deputy FBI Director Andrew McCabe and former National Security Agency Director Michael Hayden, according to Sanders.

"They've politicized, and in some cases, monetized their public service," Sanders said during a press briefing. "Making baseless accusations of an improper relationship with Russia is inappropriate."

Sanders would not say when the President would make the decision; she said only that the White House would provide updates when it had them.

Two officials on her list -- Comey and McCabe -- no longer have security clearances, people familiar with the matter said.

The announcement, made from the White House podium, came after Sen. Rand Paul, R-Kentucky, tweeted that he planned to speak with Trump about removing Brennan's security clearance.

Later, Paul wrote that in their meeting, "I restated to him what I have said in public: John Brennan and others partisans should have their security clearances revoked."

Just got out of WH meeting with @realDonaldTrump. I restated to him what I have said in public: John Brennan and others partisans should have their security clearances revoked. — Senator Rand Paul (@RandPaul) July 23, 2018

Brennan declared last week that Trump's performance following a summit with Russian President Vladimir Putin in Helsinki was "nothing short of treasonous."

A decision to strip a former official of a security clearance would prove a striking use of presidential power. Even Michael Flynn, Trump's onetime national security adviser who was fired during the Obama administration, maintained his clearance when he was acting as a campaign surrogate for Trump, often leading "lock her up" chants at political rallies.

Sanders did little to mask the political nature of Trump's threat, indicating the President was frustrated by the former officials' criticism of him.

"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 on the United States, he says that's something to be concerned with," Sanders said.

"We're exploring what those options are and what that looks like," she said of the process for removing the officials clearances.

When they leave government, national security officials routinely maintain their security clearances, partly to consult with those who replace them about ongoing situations or issues.

Officials also use their clearances to obtain high-paying consulting positions in the private sector.

"I think this is just a very, very petty thing to do. And that's about all I'll say about it," Clapper said on CNN immediately after Sanders' briefing.

"There is a formal process for doing this," he added. "But, you know, legally the President has that prerogative and he can suspend and revoke clearances as he sees fit. If he chooses to do it for political reasons, I think that's a terrible precedent and it's a really sad commentary and its an abuse of the system."

Hayden, meanwhile, indicated being stripped of his clearance would be of little consequence to his commentary.

"I don't go back for classified briefings. Won't have any effect on what I say or write," he tweeted.

The CIA declined to comment on the announcement.

JUST WATCHED Brennan on Trump's performance: Treasonous Replay More Videos ... MUST WATCH Brennan on Trump's performance: Treasonous 01:39

Trump has harshly criticized intelligence officials from the previous administration, claiming they imbued the national security ranks with politics.

"Certainly, in the past, it's been terrible. You look at Brennan. You look at Clapper. You look at Hayden. You look at Comey. You look at McCabe," Trump said during a CBS News interview last week. "Certainly, I can't have any confidence in the past, but I can have a lot of confidence in the present and the future, because it's getting to be now where we're putting our people in. But in the past, no I have no confidence in a guy like Brennan. I think he's a total low life. I have no confidence in Clapper."

It is the President's prerogative to revoke security clearances, a former senior intelligence official said on Monday, who added that instances of such an occurrence were rare.

Usually former senior officials retain clearances so their successors can consult with them on a pro bono basis, the former official said.

Steven Aftergood, director of the Federation of American Scientists project on government secrecy, said that while Trump has the ultimate authority to revoke the clearances, he would first have to ask each agency that initially granted that clearance and order them to revoke it.

Aftergood said doing that would undermine and politicize the system.

"The idea that a president or a White House would single out individuals from a past administration who have been critical and revoke their clearances is not something we have ever seen before. It's not entirely clear how it could be performed," he said. "It undermines the integrity and the neutrality of security policy which is not based on political considerations but on professional character. That system would be undermined if it became a tool for settling political scores."