Lawmakers will vote at the end of the debate on whether to seize parliamentary time on Wednesday to try and pass legislation which would force Prime Minister Boris Johnson to delay Brexit by three months.

"This is parliament's last chance to block a no-deal exit on 31st October," Oliver Letwin told parliament.

"If the House (of Commons) votes for this motion tonight, it will give itself the ability to vote for that bill tomorrow ... It is decision time."

Johnson has threatened to try and call an election if his government is defeated. Opposition Labour leader Jeremy Corbyn said his party was ready for an election.