Women scientists, engineers and technologists are being urged to return to the jobs which need their expertise.
Almost half the workforce is under-used in science and engineering
A campaign launched by the UK Resource Centre for Women in SET (UKRC) aims to help up to 1,000 women go back to the jobs for which they have been trained.
Fifty thousand are not using the specific skills they have gained in these disciplines. Such skills are considered vital to the UK economy.
Only a third go back to jobs related to their skills after time away from work.
Many of them have taken time away from the workplace to have children but face barriers when trying to return to the science, engineering and technology industries.
"This loss is contributing to a continued skills gap in the SET (science, engineering and technology) industries," said Jane Butcher, manager of the Return Campaign.
"It represents a major concern for employers, and for women, who can feel frustrated that they are not making full use of their skills and potential."
There is growing competition from India and China in these industries because they are producing and keeping so many more female graduates compared with the UK.
The campaign will offer women advice and help on how to get access to support, training, courses, mentoring schemes and networking organisations if they want to break back into their area of expertise.
The Open University is also supporting the initiative by offering a free online course.
Science, Engineering and Technology: A Course for Women Returners aims to help women work out how to get back into the industries they left, and how to update their skills.
"I've interviewed lots of women who have returned after a break and found that many face similar issues," said Clem Herman, Open University lecturer.
"For example, feeling out of touch with old contacts and networks, something which can be more acute in SET where women are still in the minority."
Many women who take a break to have a family experience similar problems in fields which move on quickly. Often they return at levels more junior than those of their peers who stayed in work.
Carol Robinson, who was elected a fellow of the Royal Society in 2004, is a professor in biological chemistry at Cambridge University. She took eight years away from work to raise her family.
WOMEN AND SCIENCE CAREERS
24,000 women with SET qualifications return to work annually but only 8,000 return to SET careers
Women with SET degrees are less economically active than male counterparts and female non-SET graduates
Women in SET are far less likely to work part-time than women in general
Now a world leader in mass spectrometry, a method used to measure the mass of individual molecules, she agrees that more women need support.
"The most difficult thing about the eight-year break was getting up to speed with the changes in information technology.
"Returning was also difficult because I had to return at a more junior level than my contemporaries who had established themselves as independent researchers.
"I've benefited enormously throughout my career from support, such as mentoring. Without this, I think on many occasions I would have been tempted to give up."
The UKRC received a boost in March when the then Trade & Industry Secretary, Patricia Hewitt, gave the centre an extra £2m from the science budget for 2007/2008.
The centre was set up as part of the government's Strategy for Women in SET, published in 2003 in response to the Greenfield Report in 2002.
It stressed the need for a national centre which could support women in SET.