Incoming Conservative government may have to call a referendum on a new European Union treaty soon after taking office.

Anti-EU campaigners are stepping up the pressure on the government for a referendum on whether the UK should leave the European Union.

A Conservative MP said that a third option in a referendum on Europe could also lead to the UK withdrawing from the EU.

David Cameron next week will order Conservative MPs to vote against holding a referendum on Britain's European Union membership.

A senior Conservative MP calls on Prime Minister David Cameron to hold a referendum on Britain's membership of the European Union.

Britain's Parliament rejected a call for a referendum on leaving the European Union on Monday (24 October), but a large-scale revolt against Prime Minister David Cameron hurt his authority and cast doubt on the country's long-term commitment to Europe. More »

Downing Street says none of the proposed changes being discussed to the future shape of the European Union would trigger a referendum in the UK.

A Conservative government could hold a referendum on the European Union's Lisbon Treaty even if it has already been ratified William Hague has said.

MPs are to debate government plans to ensure "significant" powers can only be transferred to the European Union in future after a UK referendum.

The Coalition Government will today publish details of the 'referendum lock', which would subject any future transfers of powers to the EU to a referendum in the UK. The lock will be introduced by amending the original 1972 European Communities Act and will be brought forward in the “Europe Referendum Bill”, which is set to come before the House of Commons in November.