Modest decreases in the total number of jobless has masked the fact that one worker in 10 is being denied the chance to put in more hours and earn more money, Office of National Statistics (ONS) figures show.

One million more workers have reported being underemployed since the start of the economic downturn in 2008, with the total now standing at more than three million. More than three-quarters said they wanted to increase their hours, and many had asked their employers for more work but were turned down.

Labourers, cleaners, catering and bar staff, school crossing staff and lunchtime assistants reported some of the highest underemployment rates. Len McCluskey, general secretary of the Unite union, warned that people “increasingly face a merry-go-round of insecure, low paid, part time work”.

The jobless total fell 50,000 to 2.53 million in the three months to August while the number claiming Jobseekers’ Allowance has also declined. But today’s figures suggested that many people in part-time jobs would prefer to work full time.

ONS statisticians said there were many reasons why a worker might be underemployed, including employers only offering limited hours or the job only being available at certain times, such as bar work.

Most underemployment was felt by part-time workers, with one in four saying they wanted to work more hours compared with just 5.5 per cent of full-time workers. The areas affected the most were the East Midlands, Yorkshire and The Humber.

Nearly two-thirds of the one million increase took place in the 12 months between 2008 and 2009, while the economy was in recession. Between 2000 and 2008 the number of people wanting to work more hours had remained steady. Since 2009 the figure had continued to rise, although at a much slower rate than during the recession, the ONS said.

Brendan Barber, general secretary of the TUC, said the figures demonstrated the fragility of the jobs market. “Around two and a half million across the UK are currently out of work. But this figure only tells half the story,” he said.

Andrew Sissons, a researcher at The Work Foundation, added: “Underemployment is a serious concern that is getting worse despite improvements in the labour market overall with one in 10 workers now in this position.  Not only are underemployed workers struggling to make ends meet, they are also increasing the competition for jobs.”

A Department for Work and Pensions spokeswoman said: “More than half of the 700,000 extra people in work since 2010 are working full time and we have recently seen record numbers of people in employment. “Part-time working suits millions of people… For many it is an important step to full-time work and coming off benefits.”

The Independent