Charles Kennedy uses BBC film to launch attack on the party he once led

Charles Kennedy, the former leader of the Liberal Democrats, has launched a scathing attack on his party, highlighting its failures in Government in a damning film for the BBC.

Mr Kennedy, who failed to turn up at this year's conference – despite being booked to attend a number of events – recorded the piece in London, which pointed out the difficulties the party has faced since forming the Coalition last May.

Mr Kennedy's aides blame a "family illness" for his non-attendance, but the film clearly shows his dissatisfaction with the party under the leadership of Nick Clegg.

Standing outside the Cabinet Office, where Mr Clegg now has his office, Mr Kennedy begins the film by stating: "This is Nick Clegg's rather magisterial compound in Whitehall."

He then goes on to record a roll call of the Lib Dems' difficulties in Government: tuition fees, the AV referendum defeat, electoral wipeout in Scotland and England, David Laws' resignation, Vince Cable's humiliation, Chris Huhne's indiscretions and rioting.

"In the words of the song 'If I could turn back time'," he begins. "Well, in the Lib Dems we can't. We've had 12 months of the real grind of Government and with it policy splits at the top, electoral setbacks – some of them very severe – the loss of the AV referendum and more recently and disturbingly the riots on the streets." In the five minute film he fails to mention a single Liberal Democrat achievement in Government, before concluding: "Although I take the view that former leaders should be seen occasionally and not heard too often, if I did have one wee word of advise for Nick Clegg, it would be this: at the moment there is a sense that we are trying to fight on too many fronts are the same time."

The film shows graphic images of the student riots, alongside pictures of Nick Clegg promising that he will reform Britain "for good". The clear suggestion throughout is that the Liberal Democrat leader made empty promises last year when the Coalition was formed and that the party would have been better off if it had refused to deal with the Conservatives and either triggered a fresh election or tried to build an agreement with the Labour Party.

Last night sources close to the leadership played down Mr Kennedy's comments. Privately senior MPs suggest Mr Kennedy has become an isolated figure who is bitter at the current direction of the party and angry at losing the leadership over his problems with alcohol.

"I'm afraid the days when Charles was a force in the party are long gone," said one. "That is not an ideological divide – it's just that, from week to week, he is no longer actively engaging in what's going on."