Ministers can now start work under the Act on preparing hundreds of new regulations to ensure the statute book is ready for “any scenario”, said Brexit Secretary David Davis – in a tacit acknowledgement that Britain might end up leaving without a deal agreed with Brussels.
Some MPs cheered at the announcement of Royal Assent in the House of Commons by a solemn-looking Speaker John Bercow, whose car sports an anti-Brexit sticker.
It was then repeated in the House of Lords – where some pro-Remain peers waged a hardfought battle of “parliamentary ping pong” with the elected Commons over key aspects of the legislation.
The Act enables the 1972 European Communities Act by which the UK joined the bloc to be repealed at the point of Britain’s planned exit at 11pm on March 29 next year, although ministers could change the day if necessary.
It also provides for existing EU laws affecting the UK to transfer into British law on exit day, to provide legal certainty for businesses and individuals.
Parliament may subsequently decide to scrap or amend the EU rules.
Ministers at today’s Cabinet meeting made clear their delight at the Bill becoming law, Downing Street said.
Theresa May told them it was “a historic moment for our country and a significant step towards delivering on the will of the British people”.
The legislation was “a major building block for the UK’s bright future outside the EU”.
Former Ukip leader Nigel Farage Tweeted “Hooray!” at news the Bill was now law.
Secretary of State for Exiting the EU Mr Davis said: “This is a landmark moment in our preparations for leaving the EU.
“The EU (Withdrawal) Act is a vital piece of legislation that will ensure we have a functioning statute book for exit.
“Since the Bill was introduced in Parliament last year, MPs and peers have spent more than 250 hours debating its contents and more than 1,400 amendments have been tabled.
“We will now begin the work of preparing our statute book, using the provisions in this Act, to ensure we are ready for any scenario, giving people and businesses the certainty they need.”
Some 800 pieces of secondary legislation, known as statutory instruments or SIs, are expected to be required.
As part of the first batch, the Government will use its powers in the Act to repeal the 2011 EU Act on UK procedures for agreeing EU decisions, including requiring a referendum on any treaty change which would transfer powers from Britain to the EU.
The SIs could become a new battleground for ministers and Parliament.
Such regulations do not require the same level of debate and scrutiny as full-blown Bills.
They can be agreed either by “negative procedure” where they automatically become law without debate unless the Commons or the Lords object, or by “affirmative procedure” where both Houses must actively approve the SI.
A new “sifting committee” is being created with the power to examine cases where the Government proposes to have Brexit SIs approved without debate, and recommend that the regulations undergo the scrutiny of affirmative procedure instead.