Boris Johnson vowed on Sunday to stay on as Britain's prime minister even if he fails to secure a deal to leave the European Union, saying only his Conservative government can deliver Brexit on October 31 no matter what.

At the beginning of his party's annual conference in the northern city of Manchester, Johnson wants to rally his party with the "do or die" message that he will deliver Brexit by the end of October, with or without a deal.

But there are hurdles to clear, not least of which is what Johnson calls "the surrender act" - the law parliament passed to force the prime minister to request a Brexit delay if he has not ssecured a deal with Brussels by an October 17-18 EU summit.

Johnson again declined to explain how he plans to circumvent that law and deliver on his Brexit promise, deepening uncertainty Britain's biggest trade and foreign policy shift for more than 40 years.

"People can feel that this country is approaching an important moment of choice and we have to get on and we have to deliver Brexit on October the 31st ... I'm going to get on and do it," he told BBC television.

Asked if he would resign to avoid having to ask for a delay, Johnson said: "No, I have undertaken to lead the party and my country at a difficult time and I am going to continue to do that. I believe it is my responsibility."

Opposition lawmakers have been highly critical of Johnson's reference to "the surrender bill", saying his language is stirring even more division in a country that his remained split since the 2016 referendum on EU membership.

Though the option of bringing a vote of no confidence in Johnson has been mooted in some quarters, Labour's education policy chief Angela Rayner said the party wants to "get no deal off the table" before it does anything else.

But time is running out on efforts to avoid a potentially chaotic departure from the EU, which many businesses say could hurt the economy and tip the country into recession.

The government is expected this week to present proposals aimed at overcoming the main stumbling block in talks - the border between the British province of Northern Ireland and EU member Ireland. So far the two sides have failed to agree how to prevent the return to a hard border if a any future deal fails to maintain frictionless trade.

Johnson said he is still hopeful of securing a "good deal" but added that he would not pretend it will be easy.

"It is certainly true that other EU countries also don't want this thing to keep dragging on, and they don't want the UK to remain in the EU truculent and mutinous and in a limbo and not wishing to cooperate in the way that they would like," he said.

"There is a strong view across the EU that it is time to move on."