Most employers still fail to appreciate the business advantages of breaking down gender barriers, according to the body that advises government on employment policy.
In its report on the effect of occupational segregation on the gender pay gap, the trade and industry committee said attempts to tackle the problems that deter women from taking certain jobs were only occurring in isolation.
"We are not asking business to behave altruistically, but we do expect them to behave fairly, and to be aware of the effect on their competitiveness of a failure to act," the report said.
It warned that the view that certain jobs, such as senior managerial posts, are unsuited to flexible and part-time working is still "accepted far too uncritically".
However, the committee said the right to request flexible working should not be extended as the development of best practice would be more effective than any statutory requirements, and also shied away from recommending compulsory pay audits.
The committee criticised the government for refusing to review the Equal Pay Act 1970 which it says "is reaching the limits of its usefulness".
"We regret that the government appears to be ruling changes out as 'too difficult' without having undertaken a serious review of the options", the report said.
It also calls for an investigation into the merits of a duty on the public sector to promote gender equality akin to the requirement to tackle racial discrimination.
Welcoming the Commons report, TUC general secretary Brendan Barber, said: "This report should be a spur to action for the government and employers. Its findings back up the work of trade unions and the Women and Work Commission.
"The danger is that this report will go unnoticed during the election but these issues will be at the top of our agenda when the polls close," he said. "We will continue with vigour until the whole world of work is opened up to women and the gender pay gap is closed."