(CNN)Special counsel Robert Mueller's office missed a deadline to respond to a congressional inquiry about whether he is preventing secretary of the state nominee Mike Pompeo from disclosing communications with President Donald Trump about the Russia investigation, according to a source familiar with the matter.
Mueller has not responded to Dem questions about Pompeo-Trump discussion on Russia probe
After Pompeo declined to answer certain questions about the Russia probe during his confirmation hearing last week at the Senate Foreign Relations Committee, the committee's top Democrat, Sen. Bob Menendez of New Jersey, sent a letter asking Mueller if there's "any prohibition on Director Pompeo" from answering his questions. After setting a Friday deadline, Mueller's office has not yet responded, the source said.
The push comes as Pompeo is facing stiff opposition from Democrats, who appear to have the votes to deny him majority support in committee with the help of opposition from GOP Sen. Rand Paul of Kentucky. Pompeo still may get confirmed if the GOP unites on the floor and at least one Democrat defects to support his nomination as the top US diplomat.
The Menendez letter came after Pompeo sidestepped questions about a meeting Trump reportedly had last March when the President reportedly complained about then-FBI Director James Comey, and urged his top intelligence official, Dan Coats, to persuade Comey to back off the investigation into the former national security adviser, Michael Flynn. Pompeo was in attendance at the meeting, according to The Washington Post.
During his testimony last week, Pompeo would not discuss what Trump said to him and Coats at the meeting.
"Senator, I'm not going to talk about the conversations the President and I had," Pompeo said. "I think it's in this setting appropriate for a president to have an opportunity to talk with his senior leaders."
While Pompeo insisted repeatedly that Trump did not ask him to do anything "improper," he was pressed by Menendez to say whether Trump asked him to do "anything as it related to that investigation."
"Senator, I don't recall -- I don't recall what he asked me that day precisely," Pompeo added.
Pompeo later confirmed that he has spoken with Mueller's team as part of the investigation, but he would not say if Mueller asked him not to speak about his conversations with Trump and other matters related to the investigation, prompting the Menendez letter.
A spokesman for the special counsel declined to comment when asked if Mueller's team planned to respond to the letter.