The union conducted a survey on flexible work in conjunction with campaigner Mother Pukka and had almost 13,000 responses.

Most (86%) mums working flexibly said that they have faced discrimination and disadvantage at work as a result of their working pattern.

The TUC is calling for a legal right to flexible work to be advertised with every job, as the government consults on new rights.

The legal ‘right to request’ flexible working has been in place for about 20 years. But the TUC says its survey shows the current system is broken. One in two (50%) working mums told the TUC that their current employer had rejected or only accepted part of their flexible working request.

The TUC says too many workers have their requests turned down – and those who get flexible working face discrimination and disadvantage as a result.

Many women told the TUC they are put off asking for flexible working. Two in five (42%) said they were worried about their employers’ negative reaction. Others (42%) thought there was no point asking as it would just be turned down. Only one in 20 (5%) working mums who hadn’t made a flexible working request said it was because they didn’t need it.

Two in five (42%) mums told the TUC that they wouldn’t feel comfortable asking about flexible working in a job interview because they thought they would be discriminated against.

The TUC points out that flexible working isn’t just home working – it also includes options like job sharing, agreed predictable hours, term-time working, flexitime and condensed hours.

The TUC argues that support for flexible work being the default or normal way of working is “overwhelming”. More than nine out of 10 (92%) of working mums who currently work flexibly told the TUC they would find it difficult or impossible to do their job without it.

Frances O’Grady, TUC general secretary, said: “There is overwhelming support for mums and all working parents to be able to work flexibly to manage their work and caring commitments.

“It’s time to make flexible working the norm as we emerge from the pandemic. It’s the best way to keep women in work and to close the gender pay gap. But the current system is broken. Employers still have free rein to turn down requests for flexible working. And women are too scared to ask for flexible working at job interviews, for fear of being discriminated against.

“Ministers need to do more than just tinker with a flawed system. They need to change the law so that all jobs are advertised with flexible options clearly stated, and all workers have the legal right to work flexibly from their first day in a job.”

Anna Whitehouse, founder of Mother Pukka, said: “I started the Flex Appeal movement after my flexible working request was denied in 2015. I asked to arrive 15 minutes earlier so I could leave 15 minutes earlier to make nursery pick-up. My request was denied for fear it might ‘open the floodgates’ to others seeking flexibility.

“I left, I quit, I broke and I felt redundant – like the 54,000 women every year who lose their jobs for simply having a baby.”