MercoPress. South Atlantic News Agency

Even Tories tell Johnson to be “mild in language”; stepped security for several threatened MPs

”The best way to honor Jo is for all of us (no matter our views) to stand up for what we believe in ... but never to demonize the other side” argued Johnson

UK Prime Minister Boris Johnson faced an angry backlash on Thursday over his quip about a murdered MP during a raucous parliamentary debate on Brexit. Johnson went on the offensive when MPs returned to work Wednesday following a Supreme Court ruling calling the chamber's suspension in the run-up to Brexit unlawful.

He refused to apologize and repeatedly slammed parliament for passing a “surrender act” requiring him to seek a Brexit delay past the Oct 31 deadline if he fails to reach an exit agreement with the EU.

But the real uproar came when Johnson said the best way to honor Jo Cox - a Labour MP who was fatally shot and stabbed by a man shouting “Britain first” during the 2016 EU referendum campaign - “would be, I think, to get Brexit done”.

“Feel a bit sick at Jo's name being used this way,” her husband Brendan tweeted.

”The best way to honor Jo is for all of us (no matter our views) to stand up for what we believe in ... but never to demonize the other side.“

Opposition Labour Party leader Jeremy Corbyn accused Johnson of using language that was ”indistinguishable from (that of) the far right“.

Even some members of Johnson's Conservatives appeared taken aback.

”At a time of strong feelings we all need to remind ourselves of the effect of everything we say on those watching,“ Culture and Media Minister Nicky Morgan said.

And Jacob Rees-Mogg, a strong Brexit and Johnson supporter who represents the government in parliament, noted that everyone ”had a responsibility to be mild in our language”.

Security has been stepped up around a number of MPs who reported receiving death threats over their Brexit positions online.