Ms Maitlis grilled the former Member of Congress on the subject of transfer of power after Donald Trump cast doubt on whether he would commit to peaceful transfer of power. Speaking at a news conference in September, Mr Trump said “we’re going to have to see what happens” when asked about the subject.
The presenter also pressed Mr Mulvaney on Mr Trump’s impeachment, claiming he had broken federal law and it was not just a “media spin”.
In response, Mr Mulvaney said: “If he had broken federal law he would have been impeached.
“I’m sorry to push back on that, but that’s just an outrageous statement.
“To accuse the President of the United States of breaking federal law, that’s irresponsible.”
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Ms Maitlis then interrupted him to add that “he was impeached in the House and he was cleared in the Senate, but you know what he did in regard to Ukraine.”
She added: “And you said it happened all the time, so that’s why so many people are asking if he believes in democracy.”
In response, Mr Mulvaney said he believed the voting process would take several days and conceded that it could be “messy” and “will take some time.”
He added: “But at the end of the day, we will have an orderly result and an orderly transition or retention of power.
“It is very similar to what we went through in 2000, twenty years ago. People may have already forgotten about it, but it is still in our recent history.”
The interaction sparked debate on Twitter with some agreeing with Ms Maitlis’ interviewing style and some accusing her of being partisan.
One Twitter user wrote: “Such a brilliant presenter. Incisive. Focussed. Relentless and altogether superb to watch.”
Another user added: “Brilliant, as always. The best on the BBC, along with Emma Barnett.”
Others accused the BBC of biased coverage and breaching impartiality standards.
One Twitter user said: “The BBC states that staff can’t engage in ‘virtue signalling’ but it fronts it’s US election coverage with a right-wing demagogue, Andrew Neil. If you are going for impartiality, how is this possible?
“Either way, I’m finding somewhere else to watch. This man is an embarrassment.”
Another person added: “Biased BBC pushing the Democrat talking points.”
Ms Maitlis was recently criticised by former US National Security Adviser John Bolton after he was interrupted by her during their discussion about why he did not testify in the current US President’s impeachment trial last year.
He told Express.co.uk: “It is entirely fair to push guests on the questions. Not only is there nothing wrong with it, it is the basic part of journalism.
“What is not and should not be a basic part of journalism is being impolite and in particular interrupting the person who is trying to answer the question.
“In some circles that is considered the thing to do. Well, those circles can have each other for themselves as far as I’m concerned.”