British PM May to trigger EU divorce process by end of March

British Prime Minister Theresa May will trigger the divorce process from the European Union by the end of March, firing the starting gun on the country's biggest shift in policy since World War Two.

May, appointed prime minister shortly after Britain voted in June to leave the bloc, has been under pressure from EU officials, investors and members of her Conservative Party to offer more on her plan for Britain's exit, beyond her catch phrase "Brexit means Brexit".

In an interview with the BBC, May for the first time confirmed what many expected - that she will trigger Article 50 of the EU's Lisbon Treaty before the end of March next year.

"We will trigger before the end of March next year," May told the BBC's Andrew Marr show, referring to a the formal divorce process which gives Britain up to two years to negotiate its exit from the bloc.

Asked whether her government would prioritise immigration over access to tariff-free trade with EU countries in divorce talks with the bloc - something that has muted investment, May said only that she wanted to get the "right deal".

"I want the right deal for trade in goods and services and what we are doing at the moment ... is listening to businesses here in the UK, listening to different sectors, finding out what it is that is most important to them," she said.

To get the right deal, May was clear that she must keep her cards close to her chest, saying she would not give a "running commentary" on her negotiation or give her position away.