Sen. Mark Warner, D-Va., followed through on his warning from last week, introducing on Monday an amendment that would block President Trump from punishing ex-officials who are critical of him by taking away their security clearances.

Warner's effort to challenge Trump was prompted by the White House announcing last week that Trump had stripped former CIA Director John Brennan of his security clearance.

“President Trump is setting an extremely dangerous precedent,” Warner said, according to media reports . “He’s using the powers of his office in an attempt to intimidate and silence his opponents, and he is politicizing a process that is, by design, supposed to be non-partisan and apolitical."

[More: John Brennan ready to take legal action to stop Trump from revoking other security clearances]



INBOX - Sen @MarkWarner (D-VA), files new amendment to defense appropriations bill...

Prohibiting President Trump from removing security clearances like we saw with former CIA Director John Brennan.#BreakingNews @WUSA9 pic.twitter.com/hJQzyLT3mf — Mike Valerio (@MikevWUSA) August 20, 2018



On Wednesday after White House press secretary Sarah Sanders revealed that Brennan’s security clearance had been pulled, a statement from Trump shared with reporters cited the "risks posed by his erratic conduct and behavior" as a reason to restrict his access to sensitive information.

The White House is also reviewing the security clearances of other ex-top officials, including former national security adviser Susan Rice and former Director of National Intelligence James Clapper.

Warner, the top Democrat on the Senate Intelligence Committee, said last week that he would try to rein in Trump’s authority to rescind security clearances to prevent the president from “punishing and intimidating his critics by arbitrarily revoking security clearances.”