IMAGINE you run an hour-long Sunday politics show and the main guest at a time of unprecedented peacetime strife is the Prime Minister. What he says could have an impact on the well-being of tens of millions. Do you tear up the usual format and grill him for the full hour, or cut to a chat about a television drama, then waste more precious minutes talking to a relatively minor political figure?

The Andrew Marr Show chose the latter strategy. It is difficult to see why. A time limit on the interview might have been part of the deal with Downing Street, but the beauty of a live programme is that things can change if need be. Marr's interview with Boris Johnson was just reaching a critical juncture when the show segued to a pre-recorded interview with Dame Helen Mirren about Catherine the Great (Sky Atlantic, Thursday).

Granted, viewers might have been looking forward to hearing from Dame Helen, but the segment could have been included in a longer version of the programme placed on iPlayer. Yes, the PM’s minders would likely have moaned if the interview overran, and it is not quite cricket to go back on an arrangement, yet as we are being constantly told, we are living in extraordinary times.

As for the interview with Angela Rayner, Shadow Education Secretary, it could be justified by way of reaction to the Johnson interview. Couple of questions, job done. But we had her response, plus a rehash of last week’s Labour conference story about public schools in England, and yet more speculation on what might happen next on Brexit.

Was this a case of the BBC playing it safe when a commercial broadcaster might have gone for it with the Johnson interview and had the arguments later?

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Just as these are unusual times, so Mr Johnson is an exceptional interviewee. That was made plain once more during his encounter with Marr. It was as if the BBC man was equipped with a water pistol, delivering questions in short, sharp, well-aimed bursts, and Mr Johnson was countering with one of those water cannons he bought as London Mayor and was banned from using by the then Home Secretary Theresa May. “Whoosh!” went a torrent of metaphor and hyperbole in Marr’s direction.

It is a difficult style to combat. Interviewing Mr Johnson on the Today programme, Mishal Husain resorted to telling him to “Please stop talking”, which he laughed at and carried on. Eddie Mair managed to get further than most by being icily forensic and not allowing himself to be distracted by the Johnson bluster. Marr did a heroic job of hauling the PM back to the topic on the many occasions he tried to break free, but even this was not enough to halt the tide of verbosity.

The most newsworthy moment came towards the end of the encounter when talk turned to Mr Johnson’s friendship with American businesswoman, Jennifer Arcuri. The subject had been raised during the paper review. “A lot of people are wondering if we are going to talk about the Jennifer Arcuri affair,” said Marr during the item. “Yes, we are.” They had to, given it was the splash in the Sunday Times. Plus, Labour leader Jeremy Corbyn had criticised the show for not tackling a Minister about the story last week, when it broke.

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This time, Marr asked several times whether Mr Johnson, as London mayor, had declared any links to Ms Arcuri given her business was in receipt of public money and she had gone on publicly funded trade missions. “There was no interest to declare,” said the PM.

Over on Ridge on Sunday, the Health Secretary, Matt Hancock, adopted a similar, nothing to see here, approach to the Arcuri story, saying that everything went through the proper processes.

Next up was Brexit Party leader Nigel Farage, whose party had taken out a double page ad in a Sunday newspaper proposing an electoral pact with the Conservatives as a way to give Mr Johnson “a big, workable majority”. The PM later brushed aside the offer.

Host Sophy Ridge tackled Mr Farage on a recent speech in which he said “we’ll take the knife” to overpaid pen pushers in Whitehall who had tried to frustrate Brexit. “It would have been better to say axe,” he conceded, claiming such language was are more in keeping with political tradition.

If Mr Farage was now the vocabulary police to Mr Hancock’s traffic cop, it has hard to know what role Jackson Carlaw was playing on Sunday Politics Scotland. In the face of questioning by host Gordon Brewer, the interim leader of the Scottish Conservatives was like the office temp who had unwisely picked up a ringing phone as he was passing. No, he had not been consulted by London over new EU proposals. Nor was he going to be drawn on whether the PM would have to resign if he did not obey the law and seek a Brexit extension, as one of his own MSPs, Adam Tomkins, insisted earlier this month. Nothing had anything to do with Mr Carlaw, but he would take a message and make sure the right person received it once they returned from lunch.

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At least he did not add more intemperate words and heat to what had been a torrid week. On Marr, Helen Mirren said Catherine the Great, Empress of Russia, once advised that it was best to praise in a loud voice and scold in a whisper. How wise. It was worth having the grand dame on after all.