Im no fan of Johnson (apart from the fact that he wants Brexit to get completed) but Marr never allowed Johnson to answer a question. It's customary to allow the interviewee to participate in an interview...it makes for a better show to watch.
Andrew Marr, like all the BBC "woke" producers and broadcasters, hate the Tory's and are anti Brexit, in the extreme, so fairness and balance has been lost.
Marr is a well known leftist Marxist.