Women who have children after the age of 33 earn more than those who have children when they are younger, according to a new study.

Research by the TUC revealed that women who have children before the age of 33 earn less because they are likely to be out of work for a while, or return to a part-time job.

The report, published on International Women's Day, said younger mothers are also likely to face poor treatment at work, sometimes claiming to be forced out of their job because of issues around maternity leave.

In contrast, older women with children working full-time are more likely to earn more than childless women, often because they are in senior posts.

TUC general secretary Frances O'Grady said: "This research shows that millions of mothers still suffer the motherhood pay penalty.

"We need to do far more to support all working mums, starting by increasing the number of quality part-time jobs and making childcare much more affordable. Women in full-time, well-paid jobs shouldn't be the only ones able to both become parents and see their careers progress."

The University and College Union (UCU) said female staff in higher education were paid "significantly less" than men doing the same job.

At almost two thirds of English further education colleges, male lecturers were paid an average of £1,000 more than women, a study by the union found.

The pay gap was as high as 19%, with an average of 8% in the worst offending colleges, according to the research.

The Fawcett Society said a "motherhood penalty" still existed in UK industry, with views that mothers are less committed.

A survey of 8,000 people for the campaign group found that almost half believed women were less committed to jobs after having a baby, compared to 11% for men.

A poll of 2,000 adults by Investors in People showed that eight out of 10 women believed gender discrimination is still present in the workplace.

Fewer than a third of men believed there was no gender pay gap despite official figures to the contrary.