Former cabinet minister Amber Rudd has accused Downing Street of using language that could “incite violence”.
The MP, who quit the Conservative parliamentary party earlier this month, told the Evening Standard No 10’s recent words were seen to encourage a “more aggressive approach”.
It follows a stormy week, in which several MPs criticised the PM’s use of language during debates.
Boris Johnson has insisted he “deplores any threats to anybody”.
Speaking on a visit to the Prince Alexandra Hospital in Harlow, Essex, where he announced £200m extra for NHS cancer-screening equipment, he said intimidation of MPs was “appalling”.
In her interview with the Evening Standard, Ms Rudd, the former home secretary and work and pensions secretary, said: “The sort of language I’m afraid we’ve seen more and more of coming out from Number 10 does incite violence.
“It’s the sort of language people think legitimises a more aggressive approach and sometimes violence.”
On Wednesday, Labour’s Paula Sherriff referred to Jo Cox, the MP murdered in 2016, as she pleaded with the prime minister to refrain from using “dangerous” words like “surrender”.
Mr Johnson described her intervention as “humbug”.
The prime minister was also repeatedly challenged over his use of the words “surrender bill” and “surrender act” to describe legislation passed earlier this month which aims to block a no-deal Brexit on 31 October.
He went on to say that “the best way to honour the memory of Jo Cox and indeed the best way to bring this country together would be, I think, to get Brexit done”.
Several MPs said the prime minister should apologise for this comment during a further debate on Thursday.
Ms Rudd told the newspaper she was “disappointed and stunned” when Mr Johnson dismissed “genuine fear that a lot of women have” following the 2016 murder of Labour MP Jo Cox.
She said that the “casual approach to safety of MPs and their staff is immoral”.
In interviews with the BBC, Mr Johnson acknowledged that “tempers need to come down” in Parliament.
But he added: “I do think in the House of Commons it is important I should be able to talk about the surrender bill, the surrender act, in the way that I did.”