NICK CLEGG admitted he would never woo back Liberal Democrat supporters who believed he was guilty of "treachery", plunging his party to single figures in some opinion polls.

In a question-and-answer session at the Lib-Dem conference, the deputy prime minister spoke of the "agonisingly difficult decisions" taken over 16 months of Coalition government – particularly on student fees.

And he said: "We won't win people back who regard any compromise as treachery, any compromise as betrayal, any compromise as a U-turn."

But Mr Clegg urged his party to "stop beating ourselves up about it", adding: "On the big judgments, we have nothing to apologise for. And now we have got to look forward."

The comments came as Business Secretary Vince Cable delivered an extraordinarily gloomy speech about Britain's economic prospects, describing the challenges ahead as the "equivalent of war".

Mr Cable warned the era of ever-rising living standards was over, that people were worrying about "how to survive the next ten days to payday"– and that they were "tired of being lied to" about the economy.

He told his audience, in Birmingham: "When my staff saw my draft of this speech they said; 'we can see the grey skies, where are the sunny uplands?'

“I am sorry, I can only tell it as I see it.

"The truth is that there are difficult times ahead, that Britain's post-war pattern of ever- rising living standards has been broken by the financial collapse." The speech was delivered just hours after more bad economic news, with a report in the Financial Times that identified a further £12bn 'black hole' in the nation's finances. However, the question-and-answer session was notably easier for Mr Clegg than at last year's autumn conference, when one of his own Liverpool councillors branded him a "mini-me Conservative".

Twelve months on, there was little show of dissent, aside from a single plea for an "Obama-style" financial stimulus package, to revive the flatlining economy.

Indeed, at one point, the Lib-Dem leader appeared astonished at the lack of tough questioning, telling his foot soldiers: "Heavens – what docility. Like a North Korean conferen ce meeting!"

Mr Clegg was able to reel off a long list of his party's achievements in office, including more apprenticeships, 1m people taken out of paying income tax threshold, a better deal for pensioners and on civil liberties.

Pointing to a study that found 75% of the Lib- Dem manifesto was being delivered, Mr Clegg urged his audience: "We have got to constantly, constantly, constantly tell our side of the story."

And he won applause for defending the scale of the government's spending cuts, arguing that the terrifying Greek-style alternative was "bond traders running the country".

Earlier, Mr Clegg defended the right of senior Liberal Democrats to be "rude" about their coalition partners, at what has been dubbed the “Bash a Tory” conference.

A string of ministers have delivered risqué jokes and insults aimed at Conservative colleagues, as part of a strategy to emphasise the differences between the two parties.