The prime minister has repeatedly said he would take the country out of the European Union on October 31st "do or die" — meaning with or without a negotiated deal with the European Union — but has made abundantly clear his preferred route is to agree on a deal with Brussels.

This is unacceptable to many Brexiteers, who point out the flaws of the deal that were present when Mr Johnson himself voted against it twice in early 2019 remain in place, and that to sign the nation up to a new European treaty resembles a betrayal of the spirit of the Brexit vote.

Perhaps the greatest electoral threat to Boris Johnson now is not the official opposition Labour Party — which has drifted to a position of explicitly opposing the result of the 2016 referendum where the British people voted to leave the European Union — but is Nigel Farage's Brexit Party.