Almost two-fifths thought they were paid less than male colleagues, while 30% who had taken a career break had problems returning to work, a government-funded group found.

More than 2,000 university scientists and engineers of both sexes were interviewed as part of the Athena Project, under the Equality Challenge Unit (ECU).

Programme manager Caroline Fox said the findings "flesh out the reality behind the broad statistics and anecdotal evidence".

'Better focus'

Women's and men's membership of professional societies was similar, the survey found.

However, only 19% of the relevant women were fellows, compared with 34% of the men.

Within universities, 78% of men achieved senior lecturer or reader posts through promotion rather than through competitive application. The figure for women was 68%.

All-male panels had appointed 37% of the respondents.

Ms Fox called for a "better focus" on improving career progression for women scientists.

The research comes after the Sutton Trust, an educational charity, blamed under-funding of universities for a decline in the number of Nobel Prize winners from the UK.

The Athena Project aims to advance women in science and is funded by the Department of Trade and Industry.