This year has seen the first double dip recession in the UK for 40 years and the longest since records begun. But even as the economy shrinks, unemployment has been falling, albeit only slightly and only with any real momentum in London. Whilst many countries have experienced jobless recoveries, few have experienced jobs-filled economic contractions.

Economists across the political divide are genuinely puzzled about how well unemployment is holding up in the UK. But new research published today by the TUC suggests a possible reason - beneath the positive unemployment headlines lies a growing 'under-employment' crisis, with more and more working people unable to find enough hours to get by.

Under-employment is most commonly defined as people working part-time because they can't find full-time jobs (mainly because the ONS release monthly stats on this figure), and the number of people in involuntary part-time work has almost doubled since the start of the recession in 2008 to 1.4 million.

But this figure massively under-estimates the scale of our under-employment crisis, and TUC research has found that there are also nearly two million other workers who also want more hours in their current jobs.

In total there are 3.3 million under-employed workers across the UK, nearly a million more than in early 2008. More than one in ten workers in Britain today can't get enough hours at work - and for women that rises to one in eight.

Of course, there is a positive side to under-employment. After all, any job is definitely better than no job at all. But the TUC is concerned that what was originally a short-term response to an economic crisis is becoming an ever-more permanent feature of the labour market, and that ongoing weakness across our economy is having an unreported impact on millions of those who remain with work, but simply don't have enough to make ends meet.

Under-employment means taking a huge cut in pay; putting a real strain on the finances of workers and their families. It can also mean that people are more likely to find themselves in jobs that don't fully utilise their skills, meaning that long periods of under-employment can permanently damage careers.

The likelihood of being under-employed depends on your age, your occupation and your gender. Young people are almost twice as likely to be under-employed as any other age group. It is shocking just how few youngsters today - the most highly qualified generation ever - are able to get a job paying enough hours to get their careers started. This is a criminal waste of talent that must be tackled. With over a million young people out of work, and over half a million more under-employed, this is the toughest jobs market in decades.

Under-employment is also common in low-skilled jobs such as cleaning, waitressing and shelf stacking. Again, people in these sectors are hit by high levels of joblessness, as well as insecurity and under-employment for those that are able to find work. One in four women in low skilled work are under-employed. This isn't about women wanting to work part-time due to childcare or other commitments. Across the economy there are 1.7 million women across the UK who desperately need more hours to pay the bills.

It is time for Ministers to start taking our under-employment crisis seriously. But this will require a complete shift in economic priorities. Proper jobs paying a decent wage should be the simple core goal of the government's economic strategy. Instead, we're seeing huge infrastructure cuts that are battering the construction and engineering sectors, along with relentless attacks on basic employment rights that are making jobs less secure. Even the strategies designed to create jobs rarely amount to more than new unpaid work experience. The government can and must do better. After all, decent jobs are the only way to rebuild our economy in a way that benefits the vast majority who have had to suffer from recession and endless austerity.