A dozen former intelligence officers condemned President Trump’s “ill-considered and unprecedented remarks and actions” after he revoked the security clearance of former CIA Director John Brennan, and said security clearance decisions should be founded on national security instead of “political views.”

The group of former officers — including former Director of Central Intelligence Robert Gates, former CIA Director Michael Hayden, and former Director of National Intelligence James Clapper — said the White House’s move was politicizing these clearances.

“We have never before seen the approval or removal of security clearances used as a political tool, as was done in this case,” the former officials wrote in their statement late Thursday. “Beyond that, this action is quite clearly a signal to other former and current officials.”

The group acknowledged that Brennan has been vocal about his views on national security issues, but said yanking his security clearance was an effort to “stifle free speech.”

“Since leaving government service John has chosen to speak out sharply regarding what he sees as threats to our national security. Some of the undersigned have done so as well,” they wrote. “Others among us have elected to take a different course and be more circumspect in our public pronouncements. Regardless, we all agree that the president’s action regarding John Brennan and the threats of similar action against other former officials have nothing to do with who should and should not hold security clearances – and everything to do with an attempt to stifle free speech.”

[Michael Hayden: Revoking Brennan’s security clearance appeared to be a warning to other former officials]

White House press secretary Sarah Sanders announced Wednesday that Trump revoked Brennan’s security clearance and cited Brennan’s “erratic behavior” as a reason to restrict his access to sensitive information.

Sanders said the White House was considering revoking the security clearances of other former top officials such as Clapper and former FBI Director James Comey.

The former officials said that the decision was “inappropriate” and that actions on security clearances should solely be depended on national security.

“As individuals who have cherished and helped preserve the right of Americans to free speech – even when that right has been used to criticize us – that signal is inappropriate and deeply regrettable,” the group wrote. “Decisions on security clearances should be based on national security concerns and not political views.”

Former officials on the letter are:

William H. Webster, former director of Central Intelligence (1987-1991)

Robert M. Gates, former director of Central Intelligence (1991-1993)

George J. Tenet, former director of Central Intelligence (1997-2004)

Porter J. Goss, former director of Central Intelligence, (2005-2006)

General Michael V. Hayden, USAF, Ret., former director of the Central Intelligence Agency (2006-2009)

Leon E. Panetta, former director of the Central Intelligence Agency (2009-2011)

General David H. Petraeus, USA, Ret., former director of the Central Intelligence Agency (2011-2012)

James R. Clapper, former director of National Intelligence (2010-2017)

John E. McLaughlin, former deputy director of Central Intelligence (2000-2004)

Stephen R. Kappes, former deputy director of the Central Intelligence Agency (2006-2010)

Michael J. Morell, former deputy director of the Central Intelligence Agency (2010-2013)

Avril Haines, former deputy director of the Central Intelligence Agency (2013-2015)

David S. Cohen, former deputy director of the Central Intelligence Agency (2015-2017)