Prospect, the union for science and engineering specialists across the public and private sectors, has produced the calendar to help challenge attitudes towards women in STEM (science, technology, engineering and mathematics) occupations.

Prospect and Leonora Saunders, who photographed the women will mount a one-day exhibition of the portraits at the Royal Society on December 10.

Sue Ferns, director of communications and research, said: “As the report by Professor John Perkins showed only last ­month – and 100 years after Emily Davison died at the Derby – the UK’s gendered labour market still holds back too many women from achieving their potential.

“This is bad news for an economy that needs the skills of the entire workforce to build a high quality, sustainable recovery. We are ready to work with government, employers and educators to make a difference. We are also pleased to be the first union to join WISE.”

WISE director, Helen Wollaton said: “We need to do more to inspire girls and women to choose STEM careers. WISE wants to see women make up 30 per cent of those working in STEM occupations in the UK by 2020. Trade unions, with their tradition of campaigning for equality, can make an important contribution to this. We are delighted to support the Prospect Pioneers launch, to welcome Prospect as our first trade union member and look forward to working with them to make a bigger difference.”

Minister for women and equalities, Jo Swinson said: “It’s great that this exhibition is helping to challenge perceptions of the role of women in these industries. Women are vital to building a stronger UK economy. So it’s important that our workplaces promote an environment that motivates and supports women at all levels. Girls consistently out-perform boys at school, but this does not always translate into future success in their working lives. There are still sectors, like STEM, that are male-dominated."

This year Prospect has also produced a charter for women in STEM – supported by the TUC, and launched a campaign at the House of Commons in November, which involves MPs signing pledges to act on a number of issues of concern, one of which is women in STEM occupations.

The union will donate money from the sales to a Prospect sponsored Oxfam project in Kenya, which will help to improve the employment conditions of thousands of domestic workers in the slums of Nairobi.

The calendar is for sale at www.prospect.org.uk/pioneers. It costs £5, plus postage and packing.