Jack Straw has expressed confidence that the government can win its planned referendum on the new European Union constitution.

A vote on the controversial document is expected to come next autumn, after the next general election.

The Conservatives have pledged to campaign for a "no" vote, while the Liberal Democrats have said they are in favour of adopting the constitution.

And speaking on Sunday the foreign secretary said he was "confident" that the government would secure approval for its plan to ratify the new institutional arrangements.

Speaking at a fringe meeting at Labour's Brighton conference, he said the British public wanted the EU "to be more responsive to their needs, to be more accountable to them and to their representatives and, crucially, to be more effective at delivering on the real issues that they care about such as jobs, the environment and crime".

"That is exactly what this new constitutional treaty seeks to do," Straw argued.

He added that the referendum promised to provide "a unique opportunity to re-establish the British people's support for the European Union".

Supporters of the European cause have been critical of the government's failure to take a lead in campaigning for a "yes" vote.

But Straw insisted that the government was on track to secure the public's support, despite polls suggesting that voters are sceptical about the constitution.

"I am comfortable as to where the battle lines on this issue have been drawn and, if we can remain united and resolute I am confident that we will win," he said.