LONDON A legal challenge to the government over whether Britain's exit from the European Union will automatically take it out of the single market will be heard in court next week, the group that initiated the action said on Tuesday.
It is one of several legal battles over how Britain should go about quitting the EU and trading with it afterwards - a conundrum requiring a trade-off between Brexit voters' desire for immigration controls and the economic need for good trading terms with the bloc.
The government argues that Britain's exit from the EU, known as Brexit, will also end its membership of the European Economic Area (EEA), which provides access to the single market and its free movement of goods, capital, services and people.
Prime Minister Theresa May said on Sunday that Britain would not be keeping "bits" of its EU membership, a comment that was interpreted by financial markets as pointing to a clean break from the single market.
British Influence, the think-tank behind the challenge, says the government should approach Brexit on the basis that Britain would remain part of the EEA, which includes EU member states as well as Norway, Iceland and Liechtenstein.
A hearing will take place in the High Court in London next week, most likely on Jan. 20, said Jonathan Lis, deputy director of British Influence.
"We want the government to agree with us that we're in the EEA independently (of EU membership), and that ideally forms a cast-iron negotiating tool because it means the EU can't force us out of the EEA," he told Reuters.
He added that if the government did want to take Britain out of the single market, it would have to trigger Article 127 of the EEA Agreement, and would require parliament's approval to do so.
Lis said that would be a separate process from the triggering of Article 50 of the EU's Lisbon Treaty, the formal step required to start the process of leaving the bloc.
Article 50 is at the heart of a separate court battle pitting the government, which wants to use executive powers to trigger it, against claimants who say it needs parliament's assent. The Supreme Court is expected to rule on that case this month.
The claimants in the British Influence challenge include Peter Wilding, the group's director who campaigned against Brexit, and Adrian Yalland, a former adviser to the group who campaigned for Brexit.
(Reporting by Estelle Shirbon; editing by Stephen Addison)