Theresa May can now formally trigger Brexit negotiations after the Queen signed the Article 50 Bill.
Tory MPs cheered yesterday as Commons Speaker John Bercow announced the European Union (Notification of Withdrawal) had been given royal assent.
Brexit Secretary David Davis immediately confirmed Mrs May would invoke Article 50 by the end of this month.
That moment will start the countdown on the two-year timetable for securing a deal and leaving the bloc.
This period can be extended but only with the agreement of all member states.
Britain’s future trading relationship with the EU and any exit bill which it may have to pay are expected to be highly contentious issues in the forthcoming talks.
The two-clause legislation cleared parliament unamended despite fierce opposition in the House of Lords.
Peers ultimately backed down, allowing the bill to become law.
But Labour has vowed to continue the battle to guarantee the rights of EU nationals living in the UK and give the Westminster Parliament a meaningful vote on the deal by other means.
The party has tabled two new motions to be debated in the Lords at the end of this month.
The first would require a minister to report back to peers at an early stage on the progress being made in guaranteeing the rights of EU nationals.
The second calls for the establishment of a joint committee of the Commons and the Lords “to consider and report on the terms and options” for a vote in parliament on the Brexit deal.
Reacting to the news royal assent had been granted, Labour MP Gisela Stuart, who backed Brexit and chaired Vote Leave, said: “This is a simple yet significant step in implementing the referendum result and respecting the decision of the British people to leave the EU.
“Brexit will allow us to begin the process of national renewal, enabling us to build a robust economy, more cohesive communities and to make politicians more accountable to the public.
“In the weeks and months ahead, I would urge politicians from all parties to work together to help ensure we make the most of the opportunities that leaving the EU will provide.”