William Hague promises UK sovereignty law
Foreign Secretary William Hague has promised a sovereignty clause will be included in an EU bill to be introduced into Parliament this year.
It will make clear that EU directives take effect in the UK only by the will of Parliament, which can be withdrawn.
He told Tory members legislation would be introduced this autumn.
David Cameron first floated the idea last year but the coalition agreement only says the government will "examine the case" for a UK Sovereignty Bill.
The Conservatives argues that it would simply put Britain on a par with other EU states like Germany and that Britain, with no written constitution, currently has no explicit legal guarantee that the last word on British laws stays in Britain.
Mr Hague, who promised a "hard-headed" approach to Europe in his speech to the Conservative Party conference in Birmingham, said Britain had to "work closely" with European partners on issues like dealing with Iran and climate change.
But he said a clause would be included in the European Union Bill to place the sovereignty of the British Parliament on the statute book for the first time.
It would make clear that EU law only takes effect in the UK through the European Communities Act 1972, which Parliament may amend or repeal.
Mr Hague told the conference the government would legislate "to underline that" this autumn.
"A sovereignty clause on EU law will place on the statute book this eternal truth: what a sovereign parliament can do, a sovereign parliament can also undo.
"It will not alter the existing order in relation to EU law. But it will put the matter beyond speculation.
"And it will be in line with other EU states, like Germany who in a different constitutional framework give effect to EU law through their own sovereign act.
"This clause will enshrine this key principle in the law of the land."
When Mr Cameron first announced the plan last year, he said that, without a written constitution, there was a danger that over time UK courts might "come to regard ultimate authority as resting with the EU" - and sovereignty legislation would ensure that "ultimate authority stays in this country".
The European Union Bill will also include a "referendum lock" - which will mean there has to be a public vote before any treaties are signed transferring powers from Westminster to Brussels.