The gender pay gap for women in their 20s has halved to five per cent, new research shows.

However despite this progress, the gender pay gap continues to rise rapidly for women in their 30s and 40s, particularly when women begin to start a family, said the Resolution Foundation.

The report also says that women will still earn “significantly” less than their male counterparts over their careers due to enduring this ‘pay penalty’ and despite an improvement in pay differentials during the first decade of employment.

The thinktank compared the typical hourly pay of different generations of men and women over the course of their careers.

It found that, for workers in their 20s, the pay gap was 16 per cent among baby boomers – born between 1946 and 1965 – nine per cent among people born between 1966 and 1980, and five per cent among those born between 1981 and 2000, referred to as millennials.

“This reflects positive trends, including rising higher educational participation which women in particular have benefited from, and more women breaking into high-paying industries and occupations.”

However, a sharp rise in the pay gap after the age of 30, seen in previous generations, puts millennial women on course to face a deficit of almost 30 per cent by the time they are in their mid-40s unless there is further government intervention, the report says.

From 2018, companies with more than 250 employees will have to disclose how much they are paying in salaries and bonuses to their male and female staff.

Laura Gardiner, who wrote the Resolution report, said:

“It’s important to not overlook the positives. The rate of progress between generations is really welcome, particularly with Generation X. Even in the child-rearing years there’s still really big gains.”

But she said there were many issues related to working part-time, such as missing out on informal chats in the pub, that needed to be tackled. “I wouldn’t want to play down the policy success we’ve had, but the area where there’s probably the most we could do is around the part-time penalties, and the opportunities for promotion and progression, the cultural stuff,”