The federal government’s former ethics czar says he is “stocking up” on “gear” in order to “take the streets” in the event that President Trump removes Robert Mueller as special counsel.

“I’m concerned the assault on the rule of law is coming over the holidays when we’re distracted. It‘ll be a defining moment for the Republic,” Walter Shaub wrote on Twitter on Friday.

Shaub, an Obama appointee who quit his position earlier this year in protest against Trump, circulated a advertisement for an event sponsored by MoveOn.org, the left-wing activist group.

The event is a “rapid response protest” that will form on short notice if Trump removes Mueller from office.

“Please note that the listed date is a placeholder and will be updated to be within 24 hours of the firing, should it occur,” reads MoveOn’s notice.

The group notified participants that they must “agree to engage in nonviolent, peaceful action, to act lawfully, and to strive to de-escalate any potential confrontations with those who may disagree with our values.”

Despite Shaub’s dramatic plea, there is no indication that Trump plans to fire Mueller, who took over as special counsel in May. Some Democratic lawmakers, including California Rep. Jackie Speier, said that there have been “rumors” that Trump plans to shut down Mueller’s probe.

“The rumor on the Hill when I left yesterday was that the president was going to make a significant speech at the end of next week. And on Dec. 22, when we are out of D.C., he was going to fire Robert Mueller,” Speier said in an interview on Friday, though she did not identify her sources.

Trump himself cannot fire Mueller. Deputy Attorney General Rod Rosenstein would have to make the decision. Rosenstein is who appointed Mueller to office in May after Trump fired James Comey as FBI director. Attorney General Jeff Sessions is out of the loop because he recused himself from the Russia investigation.

If Trump wanted Rosenstein to fire Mueller, and if Rosenstein refused, Trump would have to replace Rosenstein with someone who would be willing to shut down the special counsel investigation. Trump could also fire Sessions and replace him with someone willing to fire Mueller.

Shaub, who resigned as director of the Office of Government Ethics in July, was mocked by conservatives on Twitter for his dramatic decision to stock up on “gear” in anticipation of Mueller’s firing. He clarified that the event would be a non-violent protest.

CNN reported on Friday that Mueller and members of his team will meet next week with Trump’s lawyers. The reason for the meeting is unclear.

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