Donald Trump’s ex-strategist, Steve Bannon, should face contempt proceedings if he continues to refuse to testify in an investigation of Russia and the 2016 presidential election, the US House Intelligence Committee’s top Democrat said on Tuesday. California Rep. Adam Schiff said negotiations over a closed-door interview with Bannon have stalled, as the White House will only permit him to answer 14 pre-approved “yes” or “no” questions. The committee wants to interview Bannon as part of its Russia investigation, which runs parallel with Special Counsel Robert Mueller’s probe. It has subpoenaed Bannon to appear but the interview has been pushed back three times. Bannon ‘will refuse to testify, defying subpoena and risking contempt’ Bannon’s lawyer told the committee he is barred from talking about matters during the presidential transition, his time at the White House and communications with President Donald Trump since he left in August. Schiff said Republicans and Democrats on the committee are united that these prohibitions are unacceptable and that the panel could hold Bannon in contempt. “Testifying before the Special Counsel does not obviate Mr Bannon’s obligations under the subpoena issued by the Committee. “Should Bannon maintain his refusal to return and testify fully to all questions, the Committee should begin contempt proceedings to compel his testimony,” Schiff said in a statement. Steve Bannon agrees to be interviewed by Mueller so he can avoid Russia grand jury Schiff said this White House “ban” on Bannon’s testimony covered issues between Trump’s election and inauguration, his time at the White House and communications with Trump since, even though Trump has not invoked executive privilege. The White House did not immediately respond to a request for comment and neither did a lawyer for Bannon. In related news, a source familiar with the situation said Bannon was expected to appear before Special Counsel Robert Mueller next week and would answer all of Mueller’s questions. Two people familiar with Bannon’s interview said Bannon would tell Mueller “everything” he knows. The people spoke on condition of anonymity because they were not authorized to speak on the record about details of the interview. Bannon is expected to face questions about key events during his time in the White House including Trump’s firings of former National Security adviser Michael Flynn and former FBI Director James Comey. Reuters reported on Monday that Bannon would not testify before the House committee on Tuesday, despite a subpoena requiring him to appear. The panel wants him to appear again to follow up on a January 16 appearance that failed to satisfy some of its members. House Intelligence is one of three congressional committees investigating Russia and the 2016 US election, after US intelligence agencies found that Russia attempted to influence the campaign on Trump’s behalf. Moscow denies meddling in the presidential election, and Trump denies any collusion between his associates and Moscow.