UK Prime Minister David Cameron promised a referendum on EU membership if he won a second term in office.
Eurosceptism remains high in Britain with the UK Independence Party (UKIP) – which campaigned for the country to leave the EU – taking third place in the popular vote, even if it only won one seat in parliament.
Some analysts think Cameron’s re-election paves the way for a Brexit – a British exit from the EU.
For more on the impact of any referendum, euronews spoke with Wolfgang Ischinger, Chairman of the Munich Security Conference and a former German ambassador to Britain.