Part-time work can attract attract "pitiful" pay, the TUC says
The number of people in part-time work only because they cannot find a full-time job is at its highest level in 15 years, the TUC has said.
One in nine part-timers now find themselves in that position, it said, which it claimed reflected the lengths people would go to to stay in work.
There were now 829,000 people working part-time involuntarily, the TUC said, the most since 1994.
Unemployment figures due on Wednesday are set to rise sharply again.
The most recent set of data said unemployment in the UK had risen to 2.1 million, up 486,000 from a year ago.
And the TUC warned that the new figures would show the jobless total was on course to hit 2.5 million by the summer.
The lack of full-time work was demonstrated in Jobcentres across the UK, the TUC said in its analysis of official statistics, with more than a quarter of job vacancies being for fewer than 16 hours a week.
Most involuntary part-time workers are female, the TUC added, with 451,000 compared with 378,000 men.
About 20% of men working part-time are doing so because they cannot secure full-time work, compared with fewer than one-in-10 part-time women, the study found.
People moving to part-time work often were on poor rates of pay, while at the same getting insufficient hours, it added.
"As unemployment rises, people are doing whatever they can to stay in work," said the TUC's general secretary, Brendan Barber.
"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 that more action was needed to tackle job losses.
"People are far more concerned about their jobs [than cutting public spending] and tackling unemployment is the only way to get our economy motoring again," Mr Barber said.