The West Coast Express provides weekday service between Mission and Vancouver along a 65-kilometre route. (West Coast Express)

Commuter rail service linking Mission to downtown Vancouver could come to a grinding halt if a there is a strike by Canadian Pacific Railway employees.

CP Rail provides the operating crew for the West Coast Express. Unionized workers have issued strike notice and could be off the job by Wednesday morning.

"CP Rail will be in a strike position as of Wednesday morning just after midnight so that could potentially impact Wednesday's commute but we are hopeful that CP will meet their obligations and commitments to us and have those trains operating," said Fred Cummings with the BC Rapid Transit Company.

He said the company is developing contingency plans if service is derailed.

"We are working quite closely right now trying to draw up those plans with the Coast Mountain Bus Company," he said.

"But with 6,000 people a day, it's going to be very difficult to serve them with buses. There aren't that many spare buses in the system, so we won't be able to match all of the demand with buses but we will see what we can do."

The union says the company is demanding major concessions on pensions, work rules and wages.

CP says talks continue with the union,Teamsters Canada Rail Conference, which represents 5,000 employees.