More than a fifth of working-age adults in the UK are deemed not to be actively looking for work, figures suggest. Long-term illness has been cited as the main reason for about a third of the working-age inactive population not being in the labour force. It added there had been an increase in people aged 16 to 34 becoming economically inactive, but that the number aged 35 to 64 had fallen.  A recent report suggested people in their early 20s were more likely to be not working due to ill health than those in their early 40s, with cases of poor mental health believed to be on the rise.