A group of Sikh truck drivers is expected to file a Ontario Human Rights Commission complaint against Canadian Pacific Railway Thursday, over a policy that requires them to wear hard hats instead of their turbans.

According to the Toronto Star, about 500 Punjabi drivers are fuming over a rule that prohibits them from driving into CP Rail's two Greater Toronto terminals.

"Please be advised that as per CPR's Safety Policy, all drivers required to enter CPR property as well as customer locations are required to wear a hard hat. There are no exceptions to this policy," reads the memo issued by CP Rail on Aug. 1.

"We understand that this might be a concern for some drivers who are required to wear turbans as part of their religious doctrine… There is zero tolerance at CPR with regards to this requirement."

Paul Thurston, a spokesman for CP Rail, said they are concerned someone could be struck by objects in the yards, a suggestion dismissed by Major Singh, a representative for the drivers.

"We fought for the Brits in the First and Second World Wars wearing turbans," said Singh, who has worked at the rail terminals for seven years, told the Star.

"There have been no incidents of drivers being injured at the site. This is uncalled for. It completely violates our freedom of religion. This is discrimination."

While CP Rail has suggested the truck drivers could remove one of the two parts of their six-metre long turbans, the truck drivers say they don't like that idea.

On Monday, they protested the policy by staging a four-hour job-stoppage yards in Vaughan and Etobicoke.

Meanwhile, the company has granted a two-month grace period before enforcement is wholly implemented.

Still, the drivers have indicated they will go ahead with their human rights complaint.

Turbans became a point of contention in the Canadian rail industry in 1978 when a Sikh man was fired from the CN yards on Toronto's Spadina Avenue for refusing to wear a hard hat instead of his turban.

A Canadian Human Rights Commission decision found the complainant had been discriminated against.

But seven years later, the Supreme Court of Canada ruled that employers do not infringe upon human rights law when they ban Sikhs from wearing turbans on the job.