Guy Verhofstadt, the EU’s Brexit chief, displays on his phone the letter sent by Mr Johnson containing what is titled a “fair and reasonable compromise”

The European Union could grant another Brexit delay even if the letter making a request for an extension beyond October 31 is not signed by the prime minister.

European leaders are on standby to hold an emergency Brexit summit in the last week of the month if Boris Johnson fails to get a new withdrawal agreement past the House of Commons in the next two weeks.

Under the terms of the Benn act, the government must ask for a further extension to the Article 50 process if he does not have Commons approval for a new agreement or the support of MPs for a no-deal Brexit by October 19.

Mr Johnson has said repeatedly that he will not comply with the legislation but it is