Stockton South MP James Wharton said that despite the setback to his plans to give people a say on Europe by the end of 2017, Britain remained in a "very strong bargaining position".
Asked if attempts to renegotiate the UK's relationship with the EU, which would require Treaty changes, were "fantasy politics", Mr Wharton replied: "The policy is we will try to renegotiate and get a better deal."
Mr Wharton said: "I think that can be achieved. We're in a very strong bargaining position in this country. But whatever the result of that renegotiation it will be put to an in-out vote for the British people.
"It's about time that whether you want to be in Europe or you want to come out that people were allowed to decide. It's been over a generation since we last had a say."
Supporting the Prime Minister and party leader, he added: "David Cameron has committed to delivering that referendum. The Conservative Party will have it in our manifesto at the next election, whatever has happened to my Bill or happens to any future Bill, and there will be a clear choice for people: if they want a referendum... they will need to vote Conservative to get one."
Mr Wharton's comments come after Mr Cameron vowed to bid to enshrine in law his commitment to stage an in-out referendum.