The tone of the Brexit debate has become unacceptable, the Church of England’s bishops have said, as the prime minister faced intense criticism over his provocative rhetoric.

The bishops released a joint statement on Friday, calling on people both inside and outside parliament to treat each other with greater respect. They spoke after a host of MPs complained of receiving threats and Boris Johnson’s senior aide suggested that only carrying out Brexit would calm the tensions.

“In the last few days, the use of language, both in debates and outside parliament, has been unacceptable,” the bishops wrote.

“We should speak to others with respect. And we should also listen. We should do this especially with the poor, with the marginalised, and with those whose voices are often not heard in our national conversation. We should not denigrate, patronise or ignore the honest views of fellow citizens, but seek to respect their opinions, their participation in society, and their votes.”

And they offered thinly veiled criticism of the prime minister, who this week insisted the supreme court made the wrong decision in declaring his prorogation of parliament unlawful. “We call on politicians to adhere rigorously to the rule of law and on all to respect and uphold the impartiality of the courts and our judiciary,” the bishops wrote.

We should not denigrate, patronise or ignore the honest views of fellow citizens, but seek to respect their opinions Letter

They added: “Our concern is also for the structure and the constitution of the United Kingdom. To use the words of Jesus, we must renew the structures that enable us to ‘love one another’. Changes to our principles and values of government, if necessary, should be through careful planning and consultation.

“It is easy to descend into division and abuse – climbing out and finding unity again takes far longer. Further entrenching our divisions, whether from uncertainty or from partisanship, is not worthy of our country nor the leadership we now need. We are a body that understands from our own experience the dangers of division. It is our view and most solemn warning that we must find better ways of acting.”

The bishops said they made the statement “conscious of the great challenges to our nations and to their leaders. In writing, we affirm our respect for the June 2016 referendum, and our belief that the result should be honoured”.

Their comments followed an emotionally charged day in Westminster, where Johnson insisted he had every right to use the rhetoric of war when referring to Brexit, in the face of complaints from MPs that to do so would embolden those who might harm them and their families.

Play Video 0:58 Boris Johnson says he ‘deplores threats’ but will continue using same language – video

Johnson’s senior aide, Dominic Cummings, also told an audience in Westminster on Thursday it was “not surprising some people are angry” because the Brexit process was still going on more than three years after the referendum.

“I know people on both sides of leave and remain who have had serious threats … and it is obviously bad. In the end, the situation can only be resolved by parliament honouring its promise to respect the result,” Cummings said.

Earlier in the day, he had shrugged off the concerns of the MP Karl Turner, who told him he had received death threats, saying: “Get Brexit done.”

The previous day, the prime minister had provoked shock in the Commons when using similar language in reference to the memory of Jo Cox, the Labour MP who was murdered by a far-right fanatic during the referendum campaign.