A vote in the House of Commons will today determine whether the plan for the PM to leave the EU on 31 January has the support of the MPs.
EU law prohibits the Government from extending the period of transition.
Prime Minister Boris Johnson said that this will end the delay and provide certainty.
But critics have said that the law will mean that the future for the UK will be one of uncertainty and a trade agreement with the EU can take many years to come into effect. However the Government insisted that there will be a deal by the end of a transition period.