ED Miliband says he is confident of winning next year's UK general election.

The Labour leader used a speech to the Scottish Parliamentary Journalists' Assoc­iation to hit back at critics who have questioned his leadership in recent weeks.

He also confirmed a Labour Government would consider creating border controls between an independent Scotland and the rest of the UK, if the two countries pursued "markedly different" immigration policies.

Speaking in Edinburgh, Mr Miliband argued his party's commitment to social justice would win the "battle of ideas" in the run-up to the May 2015 poll, and also this September's referendum campaign.

His comments followed a bruising couple of weeks, despite Labour's continued lead over the Tories in the polls.

Former Cabinet ministers Lord Mandelson and David Blunkett offered only lukewarm support for him in recent separate interviews, while the Labour leader was ridiculed over pictures showing him eating a bacon sandwich.

Meanwhile, he has come under sustained attack by opponents on both sides of the Border. The SNP stepped up its onslaught yesterday, branding him "more unpopular than ever" and claiming the Conservatives were poised to return to power next year.

But Mr Miliband insisted: "Today I believe we are in a position to win. There have been some attacks on me in recent weeks.

"I think from some quarters they are not a sign people feel we are destined to lose, they are a sign people fear we are going to win. That's what we are planning to do."

The Labour leader added: "I'm determined and confident this is our election to win." Mr Miliband said the SNP was "banking on a Tory recovery" in the hope it would boost support for independence.

He said Labour's plans to hand Holyrood greater powers, including more control over income tax, would be in the party's election manifesto and gave "clear commitment" they would feature in his government's first Queen's Speech, if elected.

Speaking for the first time on the question of border posts, he said: "I think it is certainly the case that we would have to look at the issue of a border if you have different immigration policies. It totally stands to reason. If you have markedly different immigration policies, obviously that becomes an issue between Scotland and the rest of the UK."

His comments confirmed warnings by shadow home secretary Yvette Cooper in April and shadow chancellor Ed Balls during a visit to Edinburgh on Thursday.

First Minister Alex Salmond has unveiled plans for a modest increase in immigration, to help boost the economy, if Scots vote Yes.