Labour has warned that ordinary working people will lose more than £6000 while David Cameron is in Downing Street as it attempts to head off accusations of drift from its own MPs.

Chris Leslie, Labour's shadow financial secretary to the Treasury, said that Mr Cameron would "go down in history as a disastrous Prime Minister for people's living standards".

Labour said that the impact of falls in 'real' wages meant working people will have lost an average of £6660 by 2015 - a figure that could be even higher in Scotland. While employees across the UK have lost an average of £1350 a year in real terms since 2010, in Scotland that figure is £1420.

Quoting analysis of Office for Budget Responsibility forecasts by the House of Commons Library, Labour also said that no other Prime Minister in history had presided over 36 months in which real wage levels fell.

"He is out of touch, his economic policies have failed and the result is working families are massively out of pocket," Mr Leslie said.

Its analysis received support from the Joseph Rowntree Foundation which warned that the next election is likely to be the first since 1931 when living standards are lower than at the previous election.

The Tories dubbed the living standards briefing a "relaunch" and said it had failed before it had even started.

In a statement, the party said that Labour had nothing new to say and that Mr Miliband was "too weak" to get his Shadow Cabinet to "go out and bat for him".