Britain’s Deputy Prime Minister and leader of the Liberal Democrats Nick Clegg addressing his party’s autumn conference at the Clyde Auditorium in Glasgow yesterday. Photo: PA Wire

In his final conference speech before next year’s general election, Nick Clegg acknowledged that the Liberal Democrats had been tainted by office but insisted they still represent the “decent, British values” held to by voters.

The Deputy Prime Minister said only his party can offer voters both economic competence and social fairness in next May’s poll, which they will fight on a platform of “opportunity for everyone”.

He accused David Cameron and Ed Miliband of lurching to the right and left in response to the challenge of Ukip and the SNP, and claimed that only the Lib Dems were refusing to “trade in fear” and standing firmly against the “un-British” politics of “blame and grievance” represented by Nigel Farage’s party.

In an apparent recognition that his personal unpopularity risks harming his party’s chances next May, the Lib Dem leader acknowledged that he was no longer the “untainted... fresh-faced outsider” who sparked Cleggmania in 2010 and vowed he would never repeat the “mistake” of his U-turn on university tuition fees.

He pleaded with the electorate not to judge him solely on the fee hike, but to give Lib Dems credit for policies like income tax cuts, better pensions, help in schools for disadvantaged children, free childcare, enhanced parental leave and investment in green energy.

Insisting the party had “an extraordinary record” in office, he asked voters: “How will you judge us? By the one policy we couldn’t deliver or by the countless policies we did deliver in Government?”

In a 52-minute address concluding the annual gathering in Glasgow, Clegg cheekily offered his thanks to Miliband and George Osborne for helping to highlight the Lib Dem message with their own conference speeches – in which the Labour leader failed to mention the national deficit and the Chancellor promised tax cuts for the wealthy while slashing £3 billion from benefits for the poor.

“Let’s face it, they couldn’t have been more helpful even if they’d tried,” he joked.

“Fairness without a strong economy does not work. A strong economy without fairness doesn’t work either.

“And – as the last few weeks have now put beyond doubt – there’s only one party with the head and the heart, the resolve and the compassion, to deliver both, to deliver opportunity for everyone – and it’s us.”

He accused Cameron of stealing the Lib Dems’ flagship pledge of a £12,500 income tax threshold. And he risked angering Tories by breaching the confidentiality of behind-the-scenes coalition discussions to reveal that the Prime Minister and Chancellor had privately dismissed previous hikes in the personal allowance as “your tax cut, Nick” fit only for a “Liberal Democrat budget”.