Labour’s slip in the opinion polls after David Cameron’s impressive but duplicitous speech to Tory conference should worry everyone hoping to see the back of this conservative coalition.

Leaders’ speeches, lapped up by the adoring faithful, often give parties a bounce in the charts.

This didn’t happen with Labour because of Ed Miliband’s “look, no notes” disaster of a conference speech.

It wasn’t just that he omitted to deal with the current deficit — which isn’t as central an issue as politicians and pundits make out — but that his speech, like conference itself, lacked the substance to enthuse.

A gaggle of comfortably off new Labourites have pounced on the speech and the dip in party popularity to snipe at Miliband and seek to undermine him by touting a new leader barely seven months before the election.

John Prescott was first out of the traps with a piece that was as confused as you’d expect it to be.

Prescott was right to complain that Labour had little to offer bar a mansion tax, a marginal rise in the minimum wage and the self-inflicted wound of a child benefit freeze.

However, his call to ditch “the pollsters, the focus groups and US-style politics” indicates an absence of self-awareness or proof that he slept through most of the Blair years. He’s right, of course, but perhaps not best placed to make this criticism without an accompanying mea culpa.

Others not in an ideal position to criticise the party’s mansion tax proposal are Margaret Hodge, Tessa Jowell, Lord Noon, Lord Levy, John Mills and David Mills, who — blow me down with a feather — all just happen to be multimillionaires up to their eyes in tax-worthy mansions.

Jowell is heart-broken about “typically older families who are asset-rich and income-poor … and they certainly can’t afford a mansion tax.”

Spare us the crocodile tears. This wealthy cabal is simply doing what rich people always do — defending their assets against taxation while justifying “tough” decisions to screw working people into the ground.

The Labour leadership has listened for too long to members of the richest 1 per cent who, in return for donating little more than the crumbs from their table, believe they have the right to decide on what policies are acceptable.

The reason that Miliband’s speech — like those of other frontbenchers — was generally so flat and vapid is that Ed Balls has put the blocks on any promises that could alter the balance between rich and poor.

After over four years of savage cuts introduced by the coalition, next year’s election should be a shoo-in for Labour.

It isn’t because of what Prescott terms its “far too timid” approach, which is born out of a stubborn refusal to ditch the political convergence orthodoxy that sees all three main parliamentary parties unite behind the bankers’ austerity agenda while nitpicking about how quickly it should be implemented.

Replacing Miliband with arch-new Labourites Alan Johnson, Yvette Cooper or Chuka Umunna might introduce an element of smoothness, but it wouldn’t tackle the policy deficit.

Existing and potential Labour voters are crying out for rail and utilities public ownership, a massive council house-building campaign, higher living standards for working people and an end to the cuts obsession.

Miliband should dispense with the emptiness of note-free walkabout speeches and prioritise policies that engage with the working class not the Westminster village.