Gordon Brown says sorry for spin doctor Damian 'McPoison' McBride - sort of

More than four years after he retreated from the political limelight, Gordon Brown returned with a warning that Scotland could become independent “by mistake” and a near-apology for the activities of his infamous spin-doctor Damian McBride.

The former Prime Minister has barely strayed into domestic politics and has kept a deliberately low profile at Westminster since he led Labour to a heavy defeat in May 2010.

He broke his self-imposed exile to bolster the case for Scotland to remain in the Union, making clear he was unimpressed by Tory and Lib Dem ministers who have allowed Nationalists to depict the referendum vote as “Scotland versus Britain”.

He challenged David Cameron to debate with Alex Salmond and protested about some of the “patronising” tactics employed to win No votes.

Appearing in a television interview and addressing a Westminster lunch, he was also inevitably drawn into defending his record in Downing Street.

Mr Brown, who appeared far more relaxed than during his torrid spell in power, expressed no qualms over his government’s economic performance and sidestepped an opportunity to echo Ed Miliband’s regrets over Labour’s record on immigration.

The closest he came to a mea culpa was when he was asked to apologise to the victims of the dark arts of political character assassination revealed by Mr McBride’s memoirs.

Mr Brown said: “I’m out of front-line politics and I have no great interest in reading these books. So who you’re talking about I don’t know. If there are people here who have been traduced there should be a direct apology to them.”

He added: “I knew nothing of the things I think you’re about to claim Damian McBride did. I was not aware that individuals were being traduced and it would have been wrong for that to happen.”

He said he believed Mr Miliband, whom he was widely believed to have favoured as his successor, was doing a “great job”, but warned Britain was entering a phase of multi-party politics.

The key to electoral success, he argued, would be to pick up the support of blue-collar voters. But he seemed relaxed over any threat to Labour from the UK Independence Party and took a swipe at its leader.

He quipped: “Britain wouldn't be Britain without Farage with a pint in one hand and a mystery lady in the other.”

Mr Brown made light of his recent absences from the House of Commons, but would not be drawn on whether he planned to step down as an MP at next year’s general election. He said: “I am not going to make any announcements while we are fighting a referendum.”

Describing himself as a mere “footsoldier” in the referendum campaign, the former Prime Minister delivered a passionate argument for Scotland to remain part of the UK.

But he did not stint on his criticism of the Government’s focus on the threats to jobs and the economy if Scotland votes in September to break away from the UK.

“The nationalists want people to think it’s Scotland versus Britain or Scotland versus England, and I think sometimes the government itself has fallen into this trap,” he said.

He was withering about a publicity campaign last week designed to show Scots what they could buy with the extra £1,400 a year Ministers say they could save if they remain in the Union. It included watching Aberdeen FC play all season with a few pies thrown in or affording fish and chips every day for ten weeks. He said: “I thought that was patronising.”

Mr Brown called for a positive case to be made for Scotland to remain in the Union as he warned: “Countries can be lost by mistake... It must be two visions of Scotland's future that are at stake.”

He also condemned Mr Salmond as “embarrassing”, arguing that the First Minister had made making Scotland look "small" by unfurling a Saltire flag behind Mr Cameron when Andy Murray won Wimbledon last year.

Last night Downing Street sidestepped the call for Mr Cameron to go head to head with Mr Salmond.

The Prime Minister's official spokesman said: “The Prime Minister’s view is the same as the Better Together campaign, which is they very much look forward to Alex Salmond agreeing to debate [its leader] Alistair Darling.”