MPs sitting on two parliamentary committees responded to the experience of London receptionist Nicola Thorp, who was sent home from work last May for not wearing high heels.
She raised a petition which gained more than 150,000 signatures.
The joint report of the two committees, entitled High Heels and Workplace Dress Codes, found that the Equality Act 2010 is not being applied to protect workers over dress codes.
Helen Jones, chairman of the Petitions Committee, said: “The government has said that the way that Nicola Thorp was treated by her employer is against the law, but that didn’t stop her being sent home from work without pay.
“It’s clear from the stories we’ve heard from members of the public that Nicola’s story is far from unique.”
Ms Thorp was sent home by the accountancy firm PwC, after refusing to comply with the rules of her employment agency, Portico, that she should wear shoes with heels that were between two and four inches high.
She said that wearing them all day would be bad for her feet, and that her male colleagues were not asked to follow the same rules on their clothes.
It prompted other women to claim they had been victimised by similar rules, including instructions to dye their hair blond, or wear revealing clothes.
The MPs report is recommending a campaign to ensure that employers understand the law and employees know how to complain.
However, it also notes that the law should be enforced more vigorously and that employers should be required to pay compensation.
The report says: “The Equality Act is clear in principle in setting out what constitutes discrimination in law. Nevertheless, discriminatory dress codes remain commonplace in some sectors of the economy.
“We call on the government to review this area of the law and to ask parliament to change it, if necessary, to make it more effective.”