Britain's Prime Minister Boris Johnson  Photo: AFP

 
Brexit talks with the European Union aimed at striking a ­last-minute divorce deal are getting serious, Britain said Sunday, as Prime Minister Boris Johnson prepared to update his cabinet on the state of negotiations.

In a pivotal week that could decide the future of Brexit and the fate of the world's fifth largest economy, Johnson is trying to strike an exit deal with the EU to allow an orderly departure on October 31.

But Johnson must navigate the complexities of EU politics to strike a deal at an October 17-18 EU summit and then try to convince a deeply divided British parliament on October 19 to ratify any deal.

If he succeeds, Britain will leave the bloc on October 31 with arrangements to minimize disruption at borders and preserve the complex supply chains that underpin swathes of the economy.

If he fails, Britain faces an uncertain future - lawmakers will begin a battle to delay Brexit that could end up being decided in the courts, while Johnson will fight for a no-deal exit at the end of the month to ensure his political survival.

British and EU negotiators are working through the weekend to see if they can turn proposals put forward by Johnson, which were initially rejected by the EU, into a deal that works for both sides.

"Negotiations seem to be taking a more serious turn and that's encouraging," Jacob Rees-Mogg, a Brexit-supporting Conservative lawmaker who runs the government's business in parliament, told Sky News.

"It is always difficult to put specific odds on things but it's certainly looking more positive this week than it did last week," he said.

If Britain leaves the EU without a deal, many expect serious short-term disruption with possible food, fuel and medicine shortages, and long-term damage to Britain's reputation as a safe and stable home for foreign investment.

The government says it is doing everything it can to get a deal, and that it has contingency plans to mitigate the impact of a no-deal exit.