Analysis from the Trades Union Congress (TUC) has found one in nine people are in part-time work because they cannot find full-time employment.
It was revealed this effects one in five men, compared to less than one in ten women – suggesting male workers are feeling the effects of the recession more.
TUC general secretary Brendan Barber said rising unemployment means Brits are doing whatever they can to stay in work.
"But while part-time work is better than no work at all, people will be shocked by the pitiful pay rates on offer – a disgrace that millions of women have suffered for many years," he added.
Meanwhile, the congress cites government figures as showing there is a lack of full-time work available, because more than one in four (27 per cent) vacancies in jobcentres are for fewer than 16 hours a week.
Mr Barber also claims unemployment will "almost certainly" pass the 2.5 million mark by summer.