One union has written to bosses at Avanti West Coast, which runs the inter city trains on the line which connects Lancashire to major cities north and south, to get them to change the blouses that female staff feel are inappropriate.
He said the blouses - which allow bras to be seen from the front and back - have caused alarm among women staff members and have been described as “disgraceful” and “appalling”.
Cortes has written to Avanti managing director, Phil Whittingham, as a matter of urgency, with the new uniforms due in service immediately after Easter, on Tuesday, April 19.
The union said that Avanti held no consultation with TSSA about the uniforms and that the outfit will make women targets of sexual harassment, especially late at night.
Mr Cortes said: “Women members of our union have said they are appalled and feel exposed by the blouses which show their bras from both the back and the front. This is disgraceful treatment of the workforce, which seems to be done in the name of providing the very cheapest materials available.
He said that the company should "withdraw these uniforms which make women targets, and work together with our union on finding a suitable alternative so Avanti staff, our hard-working members, have the respect they rightly deserve.”
He added: “We also want Avanti to enter into consultation with our workplace reps about replacement uniforms.”
Lancaster and Fleetwood MP Cat Smith said: “Everyone should feel safe at work, including safe from harassment.
"It’s clear women employees on the Avanti trains are uncomfortable with the new uniform which potentially makes them more vulnerable to sexual harassment at work.
"It looks awfully like the company is trying to save money by sourcing cheap materials which leave workers’ bras visible through the blouses. The company should get better materials for their uniforms, that would help staff feel more valued and less likely to be getting unwanted attention or harassment in their workplace.”
A spokesperson for Avanti West Coast, said: “The uniform has been trialled by staff from across the business and this issue was not raised. The composition of the shirt is heavier than the current uniform and conforms with international standards of grading quality.
"Our staff have the option to wear alternative items including a polo shirt, dress, or layer with other garments as part of the design and we’ll continue to work with them to take onboard their feedback”.