Government lawyers believe the decision to begin the process of leaving the EU can be made using an executive order from the new Prime Minister, a minister has said.

Cabinet Office minister John Penrose told the Commons Parliament will nonetheless “have a role” in triggering Article 50 of the Lisbon Treaty, formally starting the process of Brexit.

The House of Commons held a brief debate after an urgent question was filed on how the UK will go about beginning the process of leaving the European Union.

The question, put forward by Labour MP Helen Goodman today, came after Andrea Leadsom dropped out of the Conservative leadership race, clearing the way for Theresa May to be named Britian’s next Prime Minister.

Mr Penrose said that Government lawyers believe triggering Article 50 “is a Royal Prerogative issue”.

He added though that “democratic principles should outrank legal formalities”.

“The Prime Minister has already said Parliament will have a role, and it is clearly right that a decision as momentous as this one must be fully debated and discussed in Parliament,” he said.

He said the “precise details” of those debates had to be agreed, but he suggested there would in fact be many parliamentary discussions on “the timing and different facets of the negotiations”.

Government minister Oliver Letwin told the Foreign Affairs Committee last week that Article 50 of the Lisbon Treaty, which formally begins the process under which a state leaves the EU, could be triggered using th Royal Prerogative, a power now exercised by the Prime Minister.

But on Wednesday Ms Goodman told The Independent that this meant the decision could be taken “without parliamentary approval”.

“The Vote Leave campaign promised to take back control and restore parliamentary sovereignty and the first thing that has to be done to negotiate Brexit is to trigger Article 50 and the Government seems to be proposing to do this using the royal prerogative,“ she said.

What is Article 50?

“I think it’s quite wrong when the public was promised this was about restoring parliamentary sovereignty.”

More than 1,000 lawyers have signed a letter addressed to outgoing Prime Minister David Cameron saying the EU referendum result is merely “advisory” and not legally binding.

Arguing the vote for Brexit, which was opposed by world leaders such as Barack Obama and Christine Lagarde of the International Monetary Fund, is far from guaranteed, the group advised the Government to carefully consider whether to follow through with the British public's vote to leave the European Union.

Before Article 50 can be triggered, they say primary legislation will need to be enacted.

Brexit protest: Thousands march in London Show all 12 1 /12 Brexit protest: Thousands march in London Brexit protest: Thousands march in London A woman poses with a home-made European Union flag as Remain supporters gather on Park Lane in London to show their support for the EU in the wake of Brexit PA Brexit protest: Thousands march in London Remain supporters demonstrate in Parliament Square PA Brexit protest: Thousands march in London Tens of thousands of people gathered to protest the result of the EU referendum PA Brexit protest: Thousands march in London A majority of people in the capital voted to remain in the European Union Reuters Brexit protest: Thousands march in London Protesters chanted: “What do we want to do? Stay in the EU” PA Brexit protest: Thousands march in London The march follows a similar rally in Trafalgar Square that was cancelled due to heavy rain – but which tens of thousands of people turned up to anyway Reuters Brexit protest: Thousands march in London Britain voted to leave the European Union in a referendum by 52 per cent to 48 per cent Reuters Brexit protest: Thousands march in London But support for the Leave campaign in urban areas and among young people was significantly lower Rex features Brexit protest: Thousands march in London Marchers gathered at Park Lane at 11am and marched towards Parliament Square PA Brexit protest: Thousands march in London Some protesters held up baguettes in a display of affection for our continental neighbours PA Brexit protest: Thousands march in London The disparity between different parts of the country has promoted a four million signature petition calling for a second referendum and even a renewed push for Scotland to cede from the UK PA Brexit protest: Thousands march in London The event’s organiser, King’s College graduate Kieran MacDermott, wrote: “We can prevent Brexit by refusing to accept the referendum as the final say and take our finger off the self-destruct button" Reuters

Leading constitutional lawyer Geoffrey Robertson QC told The Independent: “I think Britain would be a laughing stock if this outmoded mechanism [the Royal Prerogative] were used by the Government to usurp the role of parliament in a democracy – a role that many Parliamentarians fought and died for in the civil wars of the 1640s.

“It’s a preposterous and undemocratic suggestion that the Prime Minister has the power to alter the fundamental basis of the British constitution without the support of MPs.

“It would surely be judicially reviewed because the so-called Royal Prerogative powers have been reviewable [by the courts] since the attempt to use it to block a case about GCHQ was defeated in 1984.