The Canadian Auto Workers' Union has cleared an important hurdle in another of its attempts to unionize Nova Scotia's three Michelin plants.

Late Wednesday afternoon, the Nova Scotia Labour Relations Board ruled the union has signed up enough Michelin workers for a certification vote, which will be held January 4th.

This is the 13th attempt by various unions over the last 30 years to certify Michelin's plants, but only the fifth try by the CAW.

Last year, the union failed to receive enough support from the company's 3,500 employees to justify a certification vote.

According to the CAW, the average wage for Michelin workers in Nova Scotia is about a dollar less an hour than Michelin's workers in Ontario. Yet, the Nova Scotia employees have never joined up.

So why does the CAW keep coming back?

"We go back because it's the request of the people in those plants," says Larry Wark with the CAW."We just don't determine every couple of years that this is a good idea."

In 1979, the Nova Scotia government introduced what has become known as the Michelin bill. The law stated that any union would have to organize all three plants at the same time, virtually scuttling any chance of unionizing the company.

Michelin has tire plants in Bridgewater, Waterville and Granton.

Calls to Michelin administrators were not returned.