In a speech set to be delivered at the Conservative party conference today (October 2nd 2019), British prime minister Boris Johnson will tell the European Union he will take the UK out of the bloc without a deal if it rejects his final Brexit offer.

The keynote speech will take place in Manchester as a 'take it or leave it' ultimatum, with Mr Johnson saying he has participated in "fair and reasonable compromise" as part of his terms and that he is ready to pull Britain out regardless on October 31st.

The premier will tell onlookers he is ready to defy legislation requiring him to extend negotiations until January 2020 if a deal is not agreed, adding: "Let's get Brexit done - we can, we must and we will."

Explaining the reasoning behind the speech, a senior Downing Street official said: "The EU is obliged by EU law only to negotiate with member state governments - they cannot negotiate with parliament - and this government will not negotiate delay."

According to details of the Brexit offer seen by the Daily Telegraph, provisions have been included for Northern Ireland to follow EU single market rules for agricultural and industrial goods for four years after the post-2021 transition period.

In 2025, Northern Ireland would either be free to move towards the UK's trading arrangements (with a hard border in place) or continue with its existing conditions.

Effectively, this would mean two borders: one in the Irish Sea and one between Ulster and Ireland. Customs checks would be needed on both sides of the border, most likely at the premises of exporters and importers.

The whole of the UK would also be in a separate customs regime and not the customs union of the EU under Mr Johnson's offer.

The prime minister must broker a deal by October 11th, with an EU summit set to start on October 17th.

However, there is no sign yet of negotiators entering what is called the 'tunnel' phase, when final details will be thrashed out under conditions of secrecy as part of last-minute meetings.