A study of almost 2,000 mothers also revealed employers’ unwillingness or inability to offer more hours was the second biggest barrier to work for working mothers.
Think tank the Resolution Foundation and social network Mumsnet found 67% of mothers in work and 64% of mothers out of work with children under 10-years blamed childcare costs.
A comparison of OECD data included in the report also showed employers in the nations with the best maternal employment rates were more likely than UK employers to offer flexible work options, including allowing female employees to set their own hours or to use accumulated hours to earn leave days.
Emma Stewart, the co-founder of flexible work organisation Timewise, said part of the problem described by the report was the result of employers’ thinking part-time work was worth less than full-time employment.
“Women’s skills remain underutilised in the labour market at all levels, in spite of the fact that what business needs most, is a diverse range of skills and experiences,” she said.
“Key to solving the issue lies in tackling the perception that part time equals ‘part value’, and in helping businesses to shape jobs at all levels in way that allows them to be worked more flexibly.
“Forward thinking businesses are already trailblazing in this area, we need to see more celebration of good practice.”
The report’s author and Resolution Foundation deputy chief executive Vidhya Alakeson said too little was being done to help mothers take on more work – particularly to reduce childcare costs and increase workplace flexibility.
“We do worse than several other countries on maternal employment – especially for single mothers and mothers of three-to-five year olds – which is precisely the group where most childcare support is being targeted,” she said.
“It’s especially worrying that current plans to reform childcare direct more support to better-off parents when it is the less well-off who would benefit most and, at the same time, save money from the public purse by taking on more work.”
Mumsnet CEO Justine Roberts called for the Government to think about childcare “as infrastructure to the economy in the same way as we think about transport or technology”.
“Enabling women who want to work or who want to work more hours to do so, brings real financial benefits to their own family income and also to the wider economy,” she said.
According to research published in 2013 by the Family and Childcare Trust, the average nursery cost for a child under two was £106.38 for 25 hours a week, or £103.96 a week for children aged over two.