I've worked in my catering job for 11 years. We were tuped over to our present employer 5 years ago. We wear a uniform of trousers (provided by ourselves), polo shirt and apron provided by them for our contract hours. If we do hospitality work (overtime) we wear black trousers, white shirt (provided by ourselves), tie and apron provided by company.

Today we have been told the company is completely rebranding so the manager is picking our uniform, shirt and apron provided for contracted hours and we have to provide trousers. For hospitality work, the manager has picked skirt, waistcoat and scarf provided by company. I asked if there was a trouser alternative as I have never worn a skirt in this job and would prefer trousers. Answer is no. So I will miss out on overtime work as I don't want to wear a skirt. Is this allowed? Is it legal to insist you wear a skirt?