Britain's government said today it will pass a new law to protect the sovereignty of the country's parliament over the European Union before the end of the year.

Foreign Secretary William Hague said the move would "reaffirm once and for all the sovereignty of our ancient parliament" in a speech to the Conservative party conference in Birmingham, central England.

Ministers also intend to legislate so that a referendum must be held before any further powers can be transferred from Britain to the EU.

Prime Minister David Cameron's centre-right Conservatives -- who took power in May in a coalition government with the Liberal Democrats -- are eurosceptic and the coalition has vowed to hand no further powers to Brussels.

Hague said the relevant legislation on the "sovereignty clause" would be brought before Britain's parliament within a couple of months.

"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," he said.

"It will not alter the existing order in relation to EU law. But it will put the matter beyond speculation."

Aides said the measure would highlight the fact that European law only has primacy in Britain because of a law passed by the British parliament in 1972, which that parliament could theoretically still change or repeal.

The principle of parliamentary sovereignty is already asserted by common law in Britain.

Hague added: "Before the year is out, we will introduce a bill to make it the law that if any future government wishes to sign a treaty giving away more areas of power, it will be put to a referendum by law."

Elsewhere in the speech, Hague insisted he had already formed "firm friendships" in Europe and that Britain would take a "hard-headed" approach to EU matters, supporting "effective cooperation, not navel-gazing."