LONDON (Reuters) - Lawyers have advised the British government that the prime minister does not need parliamentary approval to trigger the procedure to leave the European Union, government minister Oliver Letwin said on Tuesday.
Formal talks on Britain's departure cannot start until it triggers Article 50 of the EU's Lisbon Treaty, after which it has two years to negotiate the terms of its exit.
Prime Minister David Cameron, who has announced his resignation but is staying in power until his ruling Conservatives choose a new leader, says he will leave it to his successor to notify Brussels that Britain is exiting the EU.
Some MPs who voted to stay in the European Union are hoping that parliament could delay or even block any attempt to trigger those talks. A London law firm, Mishcon de Reya, has launched a legal case to demand the government obtain parliament's approval. But EU leaders have called on Britain to invoke article 50 quickly to reduce uncertainty.
Letwin, put in charge of a special unit to lay out the options for Cameron's eventual successor on the EU, told lawmakers that while he knew there were conflicting opinions over who would or could trigger Article 50, the government had been advised that the decision lay with the prime minister.
"I am advised by the government lawyers that it is a prerogative power," he told a committee of parliamentarians, adding that he was not a lawyer or "offering any opinion".
He said the issue would be decided in court in response to the Mishcon de Reya case.
Letwin also said the question of parliamentary approval was "entirely academic" as both the lower chamber, the House of Commons, and the upper chamber, the House of Lords, would have to approve repealing the European Communities Act, under which Britain joined the bloc in 1972. He did not make clear when this would take place in the exit process.
Global law firm Dentons said the decision on who has the authority to invoke Article 50 could ultimately end up in the European Court of Justice, a target of much criticism from those who campaigned to take Britain out of the EU.
A group of MPs from the Labour Party will begin an attempt on Wednesday to pass a law calling for a second referendum before Article 50 is triggered. That referendum would ask voters whether they accepted the outcome of informal negotiations on Britain's exit.
Although the bill is unlikely to become law, Geraint Davies, the lawmaker who will introduce the bill in parliament, said it would build political pressure on the EU and act as a rallying point for MPs whose constituents are demanding a new vote.
"This bill would be both a way to get the EU to the negotiating table prior to triggering Article 50 and would give the British people the opportunity to then move forward with their eyes open," he told Reuters.