Single, female and underpaid.

New research shows that single women in their 30s are among those most likely to give their employer extra hours for free.

Around 39 per cent of female single thirtysomethings work extra unpaid hours, making them more likely to do unpaid overtime than any other group in the workforce.

And they are not alone, in fact single women in every age group are more likely to do more overtime than their single male counterparts.

The figures also show that once women have children the gender gap reverses and the proportion of women doing unpaid overtime drops from 24.2 per cent to around 17 per cent, whilst the proportion of men doing unpaid overtime when they have children remains almost unchanged.

On average the weeklys amount of unpaid overtime is seven hours and six minutes a week, if employees were to be paid for the hours they are putting in, they'd be around £4,955 a year better off.

TUC general secretary Brendan Barber said ' Most people think longs hours is mainly a problem for men. But when you look at who is most likely to put in those extra unpaid hours at work the picture changes completely. Single women do more unpaid overtime than mothers, fathers and single men.

'Women who want to get on in work need to put in longer hours than anyone else, but as soon as they have children they no longer have that option. It is hardly surprising therefore that the senior levels of most organisations are male and that the gender pay gap stubbornly persists'

singles living on their own

single men
doing unpaid

single men
mean unpaid
single women
single women mean unpaid overtime (hours)
20-24 12.3% 6.4 15.5% 5.3
25-29 23.5% 6.8 30.0% 6.9
30-39 26.0% 7.7 38.9% 7.4
40-49 22.0% 7.9 30.7% 7.6
50-59 20.0% 7.3 24.0% 6.5
group in workforce % doing unpaid overtime average hours of unpaid overtime value per employee
men with children 21.7% 8.3 £6,119.30
men without children 22.6% 7.4 £5,068.93
women with children 17.0% 5.7 £3,009.58
women without children 24.2% 6.9 £4,050.80

All figures on hours are from the Government's Labour Force Survey Summer 2007 and Annual Survey of Hours and Earners 2007, and are for employees only.