The scene outside Parliament was ugly. The protesters had come to demonstrate against Covid-19 restrictions - but when they saw Keir Starmer, their attention turned. "Traitor!" they shouted. "Jimmy Savile!" Fearful for Starmer's safety, police bundled him into a patrol car. Two people were arrested.

The insults followed Boris Johnson's claim that in a previous job Starmer "spent most of his time prosecuting journalists and failing to prosecute Jimmy Savile". Starmer had nothing to do with the Savile case.

Johnson admitted this. But while he tweeted that the protesters' behaviour was "completely unacceptable", he has refused to apologise to Starmer.

Johnson's chief policy adviser Munira MirzaShe had been head of Johnson's policy unit since July 2019. resigned. "This was not the usual cut and thrust of politics," she wrote to him: "it was an inappropriate and partisanBiased. In military terms, a partisan is a guerrilla fighter. reference to a horrendous case of child sex abuse... you let yourself down by making a scurrilousInsulting, scandalous language. According to the 18th-century Dictionary of Samuel Johnson, "using such language as only the licence of a buffoon can warrant". accusation."

A senior Tory MP, Sir Roger Gale, said the "grim scenes" outside Parliament were "the direct result of the deliberately careless use of language in the Chamber". Another, Tobias ElwoodA former soldier, he is the chair of the House of Commons defence committee., tweeted: "Let's stop this drift towards a Trumpian style of politics from becoming the norm."

Brendan Cox, whose wife Jo was murderedKilled on purpose. while acting as MP, does not believe that Johnson set out to incite a mob. But, he told the BBC, "If you inject poison into politics, that has a whole set of unintended consequences... at times that can lead over into intimidation, it can lead over into violence."

Every politician knows the importance of choosing words carefully. In ancient times, rhetoricThe art of persuasion. was considered a key part of education.

Political expert Nathan Kalmoe argues that conflict is an essential element of politics. But he points out that hateful language can inflame people who are inclined toward violence. He believes this reached new heights with Donald Trump.

The New York Times columnist Charles M Blow agrees that Trump's "stoking of fear and riling of anger is deeply problematic and indeed dangerous."

Trump, he adds, "doesn't operate on an intellectual plane, but an emotional one, and the emotions he has learned to manipulate in politics are the darker ones."

Yes: The attack on the US Capitol showed how dangerous things can become when a politician like Trump sets out to whip up people's feelings. That Johnson is following the same path is deeply worrying.

No: Passion is a desirable ingredient in politics, and inevitably brings some rough and tumble with it. It would be terrible if the parliamentary debate were so bland that nobody wanted to be involved.

Or... It is fair enough to denounce an opponent's views in passionate terms if you disagree with them. But to slander him or her as Johnson slandered Starmer is completely unacceptable.