Boris Johnson’s “crass and dangerous” rhetoric will “fuel violence” on Britain’s streets, a European Commissioner has said.

Julian King, Britain’s appointee on the EU executive, made the intervention on Wednesday night after the prime minister repeatedly accused MPs of “surrender”.

Mr Johnson dismissed criticisms of his rhetoric as “humbug” after MPs raised their fears that being branded “traitors” and accused of “betrayal” was turning them into targets for violence.

Writing off concerns that another MP might be assassinated, following the murder of Jo Cox during the EU referendum campaign, the prime minister told parliament that “the best way to honour the memory of Jo Cox” was “to get Brexit done”.

His comments further enraged MPs, given Ms Cox was assassinated by a far-right supporter of Brexit because of her political views.

How the papers covered Johnson’s return to parliament Show all 11 1 /11 How the papers covered Johnson’s return to parliament How the papers covered Johnson’s return to parliament How the papers covered Johnson’s return to parliament The Independent How the papers covered Johnson’s return to parliament Daily Mirror How the papers covered Johnson’s return to parliament The Daily Telegraph How the papers covered Johnson’s return to parliament The Times How the papers covered Johnson’s return to parliament Financial Times How the papers covered Johnson’s return to parliament i How the papers covered Johnson’s return to parliament The Guardian How the papers covered Johnson’s return to parliament Daily Express How the papers covered Johnson’s return to parliament Metro How the papers covered Johnson’s return to parliament Daily Mail

The Commissioner Mr King, who is in charge of security across Europe, highlighted Mr Johnson’s comments in a post on social media, commenting: “Crass and dangerous. If you think extreme language doesn’t fuel political violence across Europe, including UK, then you’re not paying attention.”

Mr King, a civil servant by profession was originally appointed by David Cameron in July 2016, following the EU referendum.

Following up on Mr King’s comments on Thursday, a spokesperson for the European Commission said: “I think respect is the key word. We would remain everybody that respect is a fundamental value of all our democracies and it is the responsibility of each and every politician to uphold our values. History has shown us what happens when they are not respect. That is what I would have to say from our side.”

The assassination of Jo Cox did not go unnoticed in Brussels: last year the city named a square in its old town after her. The Labour MP had spent several years living in the Belgian capital while working for Oxfam.

Earlier this month Guy Verhofstadt, the European Parliament Brexit’s coordinator, also took Mr Johnson to task for his rhetoric, telling a press conference that “opposing a no-deal is not surrender”.

“This is the language of Europe’s dark past,” Mr Verhofstad said. “It implies Britain’s European allies and neighbours are enemies.”

Mr Johnson’s comments about Jo Cox were made in response to a question from Tracy Brabin, who succeeded the slain MP as representative for Batley and Spen.

European Commissioner for Security Julian King (Getty)

“Hearing from the prime minister words like the ‘humiliation act’, the ‘surrender act’ or the ‘capitulation act’ – all these words are suggesting that because we disagree with him, we are traitors, we are not patriots. Nothing is further from the truth,” she said.

“This may be a strategy to set the people against the establishment. I would like to gently suggest he is the establishment and we are still people.”

She added. “As the woman who has taken over the seat left by our dear friend Jo Cox, can I ask him in all honesty as a human being, please, please will he, going forward, moderate his language so we will all feel secure when we are going about our jobs?”

Mr Johnson responded: “The best way to honour the memory of Jo Cox and to bring this country together is to get Brexit done.”

Asked by another Labour MP, Rosie Duffield, why delivering Brexit would honour Ms Cox’s memory, Mr Johnson said: “I believe that the continuing failure to deliver on the mandate of the people has greatly exacerbated feelings and the best way to reduce that tension is to get it done. Then the whole country can move on.