Union members have been labelled "killjoys" after delegates at the TUC conference backed a motion calling on employers to carry out risk assessments on women wearing high heels at work.
The motion tabled by the Society of Chiropodists and Podiatrists demanded women wear "sensible" shoes to work because of the risk of feet problems, knee and back pain caused by high heels.
The society's Lorraine Jones said many women had to wear high heels as part of a dress code, but it did not apply to men.
"This is not a trivial problem. Two million working days are lost every year through lower limb and foot-related problems," she said.
"We are not trying to ban high heels – they are good for glamming up but they are not good for the workplace. Women should have a choice of wearing healthier, more comfortable shoes."
But delegate Loraine Monk said the motion risked the union movement being portrayed as the killjoy fashion police.
Monk said that instead of focusing on shoes, unions should include all types of inappropriate dress in the workplace.