A pressure group campaigning for an EU referendum has said today's speech by the Prime Minister is "an encouraging first step".
David Cameron revealed that if the Conservatives win the 2015 general election he will renegotiate the UK's membership of the EU and then hold an in/out referendum.
Any referendum would be held in the early part of the next parliament - by the end of 2017 at the latest - and would ask the voters to back the new deal with the EU.
The People’s Pledge is the politically independent campaign for an EU referendum.
Campaign director Chris Bruni-Lowe said the Prime Minister's speech builds on "a growing momentum" behind giving the British people a vote about Britain’s relationship with the EU.
“Trust in politicians on the EU issue is so low that only by legislating for a referendum to be held in the next parliament can David Cameron convince us that he is serious about delivering an EU referendum," he said.
“The Prime Minister’s speech today has thrown down the gauntlet to Ed Miliband and Nick Clegg to align with over 70% of people and a clear majority of their own parties’ voters who support an EU referendum.
"The People's Pledge will build on today's speech to help achieve our campaign aim of securing a majority of pro-referendum MPs from all parties at the next election.”
At Prime Minister's Questions today Ed Miliband said he does not back an in/out referendum. His aides later qualified that statement by saying Labour does not support a referendum at this stage.
Deputy Prime Minister and Lib Dem leader Nick Clegg said the priority should be the economy and building a fairer society.
"That job is made all the harder if we have years of grinding uncertainty because of an ill-defined, protracted renegotiation of Britain's status within the European Union," he said.
"That, in my view, will hit growth and it will hit jobs and that's why, in my view, it's not in the national interest."