Sen. Bernie SandersBernie SandersBiden: 'Difficult decision' to staff administration with House, Senate members Hillicon Valley: YouTube suspends OANN amid lawmaker pressure | Dems probe Facebook, Twitter over Georgia runoff | FCC reaffirms ZTE's national security risk Biden Cabinet picks largely unify Democrats — so far MORE (I-Vt.) fired back at President TrumpDonald John TrumpMinnesota certifies Biden victory Trump tells allies he plans to pardon Michael Flynn: report Republican John James concedes in Michigan Senate race MORE on Monday after Trump said special counsel Robert MuellerRobert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE should not testify before Congress about his investigation into Russia's election interference.

Sanders said in a tweet that Trump is “not a dictator” and does not get to determine whether or not Mueller will testify.

“Sorry, Mr. President, you are not a dictator,” Sanders wrote. “In our democracy, when Congress calls on Robert Mueller to testify, he will testify.”

Mueller could testify before Congress sometime this month on the findings of his 22-month long investigation.

ADVERTISEMENT

Trump on Twitter Sunday alleged Democrats seeking to have Mueller testify are looking for a “redo” after the special counsel's report concluded Trump did not collude with Russia to influence the 2016 election.

Trump previously said it was up to Attorney General William BarrBill BarrTrump tells allies he plans to pardon Michael Flynn: report Merrick Garland on list to be Biden's attorney general: report DOJ dropping charges against ex-Mexican defense minister MORE to decide whether the special counsel would testify.

Barr had said he had no objection to Mueller testifying before Congress.