Surrender: Spoken 18 times by the prime minister Boris Johnson in a half hour interview on the BBC; you have to admire the message discipline.

MPs hate this sort of war-like language being used - surrender, traitor, saboteur - which they say is not just coarsening public debate but "inciting violence".

As former home secretary Amber Rudd put it on the eve of the Tory party conference: "The sort of language I'm afraid we've seen more and more coming out of No 10 does incite violence. It's the sort of language people think legitimises a more aggressive approach and sometimes violence."

But Mr Johnson knows, rather like the £350m for the NHS plastered on the side of the Vote Leave battle bus, that this language cuts through with an electorate thoroughly fed up with the impasse over Brexit.

It is a phrase calculated to cast opponents as people colluding with foreign powers to block Brexit.


And it is being peddled out at every opportunity by the No 10 machine - just look at the Mail on Sunday's front page: "No 10 probes Remain MPs 'foreign collusion' reads the headline, as the paper talks of a plot to let Commons Speaker John Bercow send a 'surrender letter' to Brussels asking for a delay to Brexit.

Subtle it is not. But when you are on an election footing, it is critical to have a clear message which you then rinse and repeat: Mr Johnson learnt that from his old adviser and campaign guru Sir Lynton Crosby.

Research shows the average voter thinks about politics for just a few minutes a week so repetition of strong and simple slogans is key.

Mr Johnson has cast himself as the prime minister trying to deliver on the biggest popular vote in history while the establishment - be it parliament, the courts, the institutions of the EU - are colluding to frustrate him. He is "our" General in this battle with Europe and his rivals the traitors.

But for all the message discipline at the opening of the conference, the prime minister is in danger of being derailed about the other front page stories that he would rather not talk about.

And if he looked a little rattled today in his BBC interview, it may well be because he and his team are worried about a story that isn't going to go away: the scandal around his alleged relationship with female entrepreneur Jennifer Arcuri and whether he misused public funds when he was London mayor.

The Independent Office of Police Conduct is considering whether there are grounds for a criminal investigation over alleged favours granted to Ms Arcuri, after the Greater London Authority monitoring officer - an ethics watchdog - announced on Friday evening it has raised a "conduct matter" with the police watchdog for a possible investigation into misconduct in public office.

This possible probe relates to allegations reported in the Sunday Times that Ms Arcuri received £11,500 in sponsorship cash from an organisation that was Mr Johnson's responsibility as mayor, as well as privileged access to three overseas trade missions led by the now prime minister.

Image: The PM arrives for the Tory party conference in Manchester with his partner Carrie Symonds

Mr Johnson was clear on Sunday when asked whether he had declared an interest to City Hall regarding his friendship with Ms Arcuri that there was "no interest to declare".

"Everything was done with full propriety."

Meanwhile, allies such as his environment secretary Theresa Villiers, said the allegations were "politically motivated" and said it was a "distraction". And it certainly seemed to have distracted the prime minister on Sunday morning as he was buffeted from his core message into territory he would much rather not go.

He can control the messaging on Brexit, he is less in control over the Arcuri allegations and now potential police probe.

"You've got to be realistic if you're in my position," he said on Sunday morning. "And you've got to expect a lot of shot and shell."

More war analogies, and whether he likes it or not another front has opened up that could become even more difficult for him to handle than Brexit.