The Tories have accused Gordon Brown of leaving voters worse off than at the last general election.
Shadow chancellor George Osborne cited research demonstrating this is the first parliament in three decades in which national income per head is lower at the end.
The last time GDP per capita shrunk during the course of a parliament was during the short-lived minority Labour administration in 1974.
The Tories produced figures showing that it was now £281 lower than in 2005. However, during the 1997/2001 parliament it rose £2,033, followed by £1,502 between 2001 and 2005.
Labour accused Mr Osborne of talking the economy down.
The offensive came as Mr Osborne prepared to give the Mais lecture, in which he will make clear that “Gordon Brown’s debt” will be central to the Tories’ election campaign.
He will say that the country’s massive debt is its single biggest threat to Britain’s economic future.
Speaking ahead of the lecture, Mr Osborne said: “When people ask the famous question ‘are you better off than you were five years ago?’ Gordon Brown is the first prime minister in modern British history who has to answer ‘no’.”
But Liam Byrne, Chief Secretary to the Treasury, said: “Since 1997, the UK has seen the biggest increase in income per person of any nation in the G7. Of course the recession has had an impact. That’s true of every developed country, including Japan and the United States.
“Our first priority now is to secure the recovery – in contrast to George Osborne’s dangerous plan to slam on the brakes.”
Source: Press Association