16/03/2017 10:50 GMT | Updated 16/03/2017 10:56 GMT

Article 50 Brexit Bill Receives Royal Assent Allowing Theresa May To Take UK Out Of EU

Prime Minister to notify Brussels before end of March.

Bloomberg via Getty Images

Theresa May has today been granted the authority to trigger Article 50 and begin the formal Brexit process after the necessary legislation received Royal Assent.

The Queen signed the European Union (Notification of Withdrawal) Bill into law on Thursday morning.

The prime minister is now able to notify Brussels that the UK is leaving the EU and begin the two-year negotiation process.

May has said she will invoke Article 50, the legal mechanism for withdrawal, by the end of the month in what will be a “defining moment” for the country.

However the House of Lords is gearing up for a fresh Brexit challenge to May over EU citizens’ rights and a vote on a final divorce deal with Brussels, The Huffington Post UK can reveal.

This morning, Labour tabled two new motions serving notice on the Government that ministers will not be let off the hook even after the prime minister triggers Article 50.

One motion tabled by Labour seeks to force ministers to update peers on EU citizens’ rights ’by the end of’ the current Parliamentary session.

The second Labour motion calls for the creation of the creation of a Joint Committee of Lords and Commons “to consider and report on the terms and options for any votes in Parliament on the outcome of the negotiations on the UK’s withdrawal from the European Union”. It states the new committee should report by October 31 this year.

The move comes after ministers were accused of “driving towards a cliff-edge with a blindfold on”, as Brexit Secretary David Davis admitted they have made no assessment of the economic implications of failure to secure a deal with the rest of the EU.

The prime minister has declared her readiness to walk away from Brexit negotiations without agreement, insisting that “no deal is better than a bad deal”.

And Foreign Secretary Boris Johnson said in a TV interview at the weekend it would be “perfectly okay” to crash out of the EU on World Trade Organisation (WTO) terms.

European Council president Donald Tusk said the signals coming from the UK Government just weeks ahead of the start of negotiations amounted to “threats”, but insisted Brussels would not be “intimidated”.

Failure to reach agreement on a future UK-EU relationship would be worse for Britain than for the remaining 27 states, he told the European Parliament.

Davis tried to ease tensions with Brussels, urging colleagues to ensure future comments about the upcoming negotiations are “as calm as possible and as amicable as possible”.

But he was unable to provide the committee with an estimate of the cost of “no deal”, and said it might be a year before he could offer any figures.

David Davis gives evidence to the Brexit Select Committee in the House of Commons, London.

Davis confirmed that leaving under WTO rules would mean tariffs of 30-40% on agricultural exports and 10% on cars, the loss of EHIC health insurance cards for travellers and passporting rights for financial sector firms, as well as departure from the EU-US Open Skies arrangements for air transport.

But he said it will be possible to devise mitigating action in response to these issues.

“Any forecast you make depends on the mitigation you make, and therefore it would be rather otiose to do that forecast before we have concluded what mitigation is possible,” said the Brexit Secretary.

May’s “no deal is better than a bad deal” mantra was coined “in the emotional aftermath of the referendum (when) there were lots of threats of punishment deals”, said Davis.

“We had to be clear that we could actually manage this in such a way as to be better than a bad deal, and that is true.

“I can’t quantify it for you yet. I may well be able to do so in a year’s time. It’s not as frightening as some people think, but it’s not as simple as some people think.”

Shadow Brexit secretary Sir Keir Starmer accused the Government of “recklessly talking up the idea of crashing out of the EU with no deal” while making no assessment of its potential cost.

Liberal Democrat Brexit committee member Alistair Carmichael said the Government’s approach was “the equivalent of driving towards a cliff-edge with a blindfold on”.