Ed Miliband has outlined a new Labour policy on the EU, which would guarantee an in/out referendum, but only in circumstances the Labour leader describes as “unlikely”.

Labour have been under pressure to address the referendum question from the moment David Cameron promised that a Conservative government would offer the British people a vote in 2017.

The opposition will hope their new position is robust enough to withstand an onslaught from the Tories this side of the election and beyond.

Mr Miliband, writing in the Financial Times ahead of a speech on Wednesday, lays out an “agenda for change” in Europe, pledging: “We strongly believe Britain’s future is in the EU.”

Among his proposals is to extend transitional arrangements for countries joining the EU “so that citizens have to wait longer before gaining rights to work here”.

“There should be reforms to rules allowing people to claim child benefit of child tax credit when their children live abroad,” he argues.

The key initiative from the Labour leader is what he calls a “new lock: there would be no transfer of powers from the UK to the EU without a referendum on our continued membership of the EU”.

However, he points out there are no current proposals for such a transfer of powers. “It is unlikely there will be any such proposals in the next parliament.”

The Labour leader views a referendum as an unattractive, as well as an unlikely option.

The Conservative position is in certain respects just as bedevilled as Labour’s with caveats, ifs, buts and hypotheses.

But it is clear in its guarantee of a 2017 vote, no matter what.

On that basis, it is certain the Tories will accuse Mr Miliband of retreating to the fence on Europe. It is an attack he will have anticipated, and he will now spend months and indeed years trying to repel it.

Shortly after details of Mr Miliband’s pledge were revealed, Prime Minister David Cameron tweeted: “By his own admission, Ed Miliband says it’s unlikely there’ll be an in-out referendum on Europe under Labour.

“Only the Conservative Party can guarantee and deliver that in-out referendum.”