LONDON (Reuters) - Britain's deal with the European Union on new membership terms could be undone by the European Court of Justice despite support from all member states, Justice Secretary Michael Gove - a leading member of the "Leave" campaign - told the BBC.
Prime Minister David Cameron's Downing Street office rejected the argument, saying the deal was an irreversible decision in international law that required the European court to take it into account.
Gove, considered a policy heavyweight in the British cabinet, is a close friend and political ally of Cameron, but the men are on opposite sides of the debate ahead of a June 23 referendum on whether to stay in or withdraw from the EU.
Gove does not have the popular appeal of London Mayor Boris Johnson, the most prominent member of the ruling Conservative Party to come out in favor of a "Brexit", but as Justice Secretary Gove's views on the legal issues will carry weight.
"The facts are that the European Court of Justice is not bound by this agreement until treaties are changed and we don't know when that will be," Gove told the BBC in an interview broadcast on Wednesday morning.
He said Cameron was "absolutely right that this is a deal between 28 nations all of whom believe it" and said that the prime minister had "not been misleading anyone".
"I do think it's important that people also realize that the European Court of Justice stands above every nation state, and ultimately it will decide on the basis of the treaties and this deal is not yet in the treaties," Gove said.
Downing Street issued a statement rejecting Gove's line of argument.
"It is not true that this deal is not legally binding. Britain's new settlement in the EU has legal force and is an irreversible International Law Decision that requires the European Court of Justice to take it into account," it said.
Attorney General Jeremy Wright also said Gove's suggestion was not correct.
"It has legal effect from the point the UK says it intends to remain in the EU, and the European Court must take it into account," Wright said in a statement.
"That is not just my opinion – it is the opinion of this government's lawyers, lawyers for the EU, and, I suspect, the majority of lawyers in this country."
According to a YouGov poll published on Wednesday in the Times newspaper, 29 percent of people would trust Cameron on EU issues, while 17 percent would trust Gove. The most trusted public figure on the issue, by 34 percent of people, is London Mayor Johnson, according to the poll.
The YouGov poll, conducted online, found that the "Leave" and "Remain" camps were neck and neck, but a ComRes telephone poll published on Wednesday in the Daily Mail found that the "In" camp was ahead by 12 points.
(Reporting by Estelle Shirbon and Elizabeth Piper; Editing by Toby Chopra)