It is a measure of how fevered British politics has become that many MPs speak of holding elections to the European parliament as a calamity to be avoided at all costs. It would certainly be an unusual exercise for a country committed to leaving the EU, but there are worse things that could happen to a democracy than its citizens having an opportunity to vote.

The UK could be compelled to hold an MEP ballot as a condition of securing a long Brexit postponement at an emergency summit next week. But every extra day of EU membership reminds Brexiters that they have failed to deliver their cherished goal. Instead of taking ownership of this mess, many Tory MPs divert their rage onto remainers and advocates of a soft Brexit.

Fear of confronting the impossibility of achieving what was promised by the leave campaign in 2016 has driven a process of Eurosceptic radicalisation. At least half of Tory MPs now declare themselves ready to quit the EU with no deal at all. Many see that ruinous path as the only valid expression of the referendum result.

This frenzy reached new heights when Theresa May invited Jeremy Corbyn to Downing Street for talks on resolving the Brexit impasse. It is fair to question whether such dialogue can be fruitful, or is undertaken in sincerity by either side. But many Tory MPs have condemned Mrs May for the mere fact of engaging with the Labour leader on the grounds that doing so bolsters his authority in the public eye. Conservatives have many reasons to dislike Mr Corbyn’s politics, but his entitlement to be part of a Brexit process is constitutionally validated by his status as leader of the official opposition.

On the day that a video circulated online, appearing to show British soldiers using Mr Corbyn’s image for target practice, it should be clearer than ever that the temperature of Westminster politics urgently needs to come down. For too long there has been too much use of violent rhetoric and gruesome imagery; too much talk of betrayal, sabotage, treason, back-stabbing and blowing things up. Romanticisation of violence is common on the political fringes – left and right – but it has captured the mainstream.

Meanwhile, MPs’ offices have been vandalised. They receive death threats. They are mutilated in effigy at demonstrations. Earlier this week it was reported that a neo-Nazi plot to murder a Labour MP had been foiled. It is less than three years since Jo Cox was murdered by a far-right extremist.

There is no simple connection between the hyperbole of an overheated political debate and acts of terror and violence. There is still a responsibility on democratic politicians to mind their language in a febrile climate and not give succour to people who wilfully blur the boundary between aggressive language and acts of aggression. Britain is experiencing a severe political crisis that is made worse when public figures forget the boundaries of civility and abandon respect for dissenting opinion.

The current atmosphere is not conducive to making wise choices about the future. That is a reason to welcome the prospect of a long article 50 extension. If participation in European parliamentary elections is part of the price, it should be willingly paid. An objection raised is that the campaign would offer a platform for extremists, embittered by Britain’s ongoing EU membership. That is a risk, but it would say something appalling about the condition of British politics that we are afraid to hold an election because thugs would compete in it.

Brexit has been a failure on the terms set out by those who campaigned for it and within the timeframe originally provided for its delivery. That demands an adjustment of perspective and a cooling of the political temperature, not just for the sake of better decision-making but to restore lost decency to the conduct of British democracy.