Clegg urged to go now and make way for Vince Cable

Senior Lib Dem activists say the Deputy PM shouldn't wait until the next election to resign

Nick Clegg today faces a public challenge to his leadership from the Liberal Democrat grassroots, with calls for him to resign now and make way for Vince Cable.

The call comes as the Deputy Prime Minister and David Cameron prepare for a wide-ranging reshuffle this week in an attempt to shield the coalition from mounting discontent inside both Liberal Democrat and Tory parties.

The Lib Dem leader is accused by senior activists of failing to stand up for the interests of the party on tax, the NHS, Europe, education and electoral reform. It is the first time Mr Clegg has faced a public demand to quit immediately, and goes further than the call last week by one of his leading critics, Lord Oakeshott, to consider resigning before the next election. Last week, a poll for the Lib Dem activists' Voice website, found that 50 per cent of members want Mr Clegg to stand aside before 2015.

Andrew Bridgwater, vice-chairman of Devon and Cornwall regional party and chairman of the Lib Dem education association, said: "The sooner Nick resigns and creates a vacancy for Vince, the better. To put it bluntly, I would encourage Vince Cable to stand for the leadership to take us into the next election."

A Lib Dem constituency chairman, who declined to be named, also called for Mr Clegg to go now.

A third party activist, Charles West, the chairman of Shrewsbury and Atcham Liberal Democrats, said Mr Clegg must "justify" his decisions in government over the next two years or be "at risk" from a leadership challenge.

Last week, Lord Oakeshott, an ally of Mr Cable, suggested Mr Clegg should consider stepping aside before the 2015 election.

In the biggest shake-up of the Government since the formation of the coalition in May 2010, Mr Cameron and Mr Clegg will try to keep a lid on internal tensions, as they threaten to dominate the political conference season. One controversial plan being considered inside Downing Street is to make Kenneth Clarke, the Justice Secretary, Leader of the Commons and replace him with Francis Maude, the Cabinet Office minister who provoked a storm earlier this year by suggesting that motorists could store fuel in "jerry cans".

Allies of the Transport Secretary, Justine Greening, warned Mr Cameron not to move her amid the growing clamour for a decision over Heathrow. The source said: "It is not like you get rid of Justine and then you can have your third runway."

Other ministers tipped for a job-change are Eric Pickles, the Local Government Secretary, who could be made Chief Whip, replacing Patrick McLoughlin, who is likely to leave the Government. The reshuffle will coincide with a relaunched economic plan from George Osborne, who will introduce a further planning shake-up and a major housebuilding programme to encourage economic growth.

But tomorrow, Mr Cameron's former leadership rival David Davis will stoke Tory right-wing discontent with No 10 by setting out an alternative economic plan, including freeing businesses from red tape. Mr Davis and Tory MPs want Mr Cable to be sacked as Business Secretary because, they claim, he is a "road block" to economic growth.

Sources said it was unlikely that Mr Cable, who in July refused to rule out his leadership ambitions, would be moved. A senior Lib Dem source said: "Vince is doing a good job. There is no logic for moving him."

Critics of Mr Clegg complained that he had "acquiesced" to Mr Cameron in two years of coalition and insisted that Mr Cable would be better at defending Lib Dem interests as Deputy Prime Minister.

Mr Bridgwater, a member of the Liberals since 1975, said that Mr Clegg's call for a "wealth tax" last week was welcome, but pointed out that he had allowed the Tories to cut the top rate of income tax from 50p to 45p in the Budget. Mr Bridgwater's comments are all the more damning because his region is the party's original stronghold with five MPs.

He added: "Is Nick Clegg going to lead us to success at the next election? Absolutely not. We have to find another leader. It is Vince Cable."

Mr West said: "Clearly the jury is out. If [Nick] cannot justify himself, then he is vulnerable."