Voters will be asked if the UK should "remain a member" of the European Union when they go to the polls for the in/out referendum, Downing Street has confirmed.
The wording of the question that will appear on ballot papers means supporters of Britain retaining its ties to Brussels will form the "Yes" campaign.
Details of the question and a commitment to staging the popular vote by the end of 2017 are contained in a Bill introduced into Parliament as David Cameron embarks on a whirlwind diplomacy tour across Europe to garner support for his plans to renegotiate Britain's relations with the EU.
Downing Street said the measures being published provide a "concrete step" towards settling the row over Britain's links with Brussels and show the Prime Minister has been "true to his word" on giving the public a say.
Mr Cameron will meet Dutch counterpart Mark Rutte for a working lunch in The Hague before heading to Paris for talks with President Francois Hollande at the Elysee Palace.
A meeting will be held with Polish Prime Minister Ewa Kopacz in Warsaw tomorrow before talks in Berlin with Chancellor Angela Merkel, whose backing will prove crucial if Mr Cameron is to secure serious reforms. A visit to Copenhagen to meet Danish premier Helle Thorning-Schmidt was cancelled after she called a general election.
Downing Street played down suggestions earlier this week that the renegotiation has already suffered a setback following reports that France and Germany had struck a deal to integrate the core eurozone group more closely without the need for fundamental treaty change.
The Conservatives' preferred wording for the in/out referendum question - ''Do you think that the United Kingdom should be a member of the European Union?'' - has been dropped following concerns by the Electoral Commission that some people might think the country was not already a member.
'Negotiations are a fudge'
Instead the watchdog's recommended choice for voters has been adopted in the EU Referendum Bill.
It reads: "Should the United Kingdom remain a member of the European Union?"
A No 10 source said: "The introduction of the EU Referendum Bill is a concrete step towards settling the debate about the UK's membership of the EU.
"It will pave the way for the British people to have their say for the first time in 40 years on our place in the EU. And as the Prime Minister has said before, it will be an important choice about our country's destiny.
"Over two years ago, the Prime Minister made a commitment to give the British people a very simple choice in an EU referendum.
"He made clear then that this should not be on the basis of the status quo but on a reformed relationship with the EU that the PM is determined to deliver. With today's Bill, the PM has been true to his word. The question is clear. It will be for voters to decide whether to stay or leave."
Ukip leader Nigel Farage said: "It is a simple, straightforward, unambiguous question. That much is clear.
"However, that Cameron is opting to give the pro-EU side the positive 'Yes' suggests strongly that his negotiations are so much fudge. He has already decided which way he wants the answer to be given, without a single power repatriated."