Unemployment could be as high as 6.3 million in the UK if a different counting measure was used, says a new report from the TUC.
The trade unions body said the higher joblessness figure, more than twice the official total, was revealed using an American measure which includes people in part-time jobs because they cannot find full-time work and recent redundancies.
The official jobless total increased to 2.68 million last month and is expected to rise again when figures are published by the Office for National Statistics tomorrow.
But the TUC study said under-employment, which counts those doing temporary or part-time jobs because they cannot find permanent, full-time work, has risen to a record 1.3 million.
Another 2.34 million people "want work" but do not meet the official definition of unemployment because they have not been looking for work in the past four weeks or they were unable to start working within two weeks.