LONDON (Reuters) - Britain's parliament will "very likely" have to ratify the country's eventual agreement with the European Union when it leaves the bloc, a British government lawyer said on Tuesday, boosting the battered pound on currency markets.
"The government view at the moment is it is very likely that any such agreement will be subject to ratification," James Eadie, who is representing Prime Minister Theresa May's government, told the High Court in London.
He was speaking on the third day of a legal challenge by campaigners who say parliament - not ministers - should have the right to start the formal, two-year divorce procedure by triggering Article 50 of the EU Lisbon Treaty.
May has said she will start the process before the end of next March.
Although her government says it has the right to trigger Article 50 without consulting parliament, it has previously promised that lawmakers will be fully consulted over the subsequent negotiations.
Most treaty deals have to be ratified by parliament and Eadie said that would probably apply to an eventual deal on Britain's exit from the EU. "We understand it will be one of those treaties," he said.
But he added that it was possible that the EU and Britain could agree that their divorce agreement would come into effect without parliamentary approval.
Sterling, which has fallen by nearly 20 percent against the U.S. dollar since June's referendum on concerns about the impact of Brexit on Britain's economy, jumped by more than half a cent on Eadie's remarks.
"We have just jumped on that headline but it does not look as clear as people initially thought," said a strategist with one international bank in London.
(Reporting by Michael Holden; Writing by Stephen Addison; Editing by William Schomberg)