As shippers' problems worsened and U.S. union officials sniped from across the border, CN Rail and the United Transportation Union squared off on Monday in a hearing on the legality of a nine-day-old strike by conductors and yard crews.

CN asked the Canada Industrial Relations Board to rule that the UTU's Canadian branch took the 2,800 workers out on strike illegally because it failed to get clearance from the union's international headquarters in Cleveland.

About 2,800 CN railway yard workers and conductors went on strike Feb. 10.
(CBC)

The Canadian branch said it followed Canadian labour law, but the UTU's international president, Paul Thompson, has offered support for CN's claim.

He posted a statement on the union's website on Feb. 16, portraying Canadian UTU leaders as plotting to defect to the rival Teamsters union in hope of getting Teamster jobs for themselves.

"It now is shockingly apparent that this time around, the Canadian UTU general chairpersons failed to follow the UTU constitution for the apparent purpose of launching an unauthorized strike that they knew would result in financial harm to their members," Thompson said in the statement.

"This was part of their self-serving treachery to turn their members against the UTU International, avoid allowing the members to decide what union they wished to affiliate with in Canada and turn their membership over to the Teamsters."

In Ottawa, a receptionist at the UTU's Canadian headquarters said senior officials were in meetings on Monday and were not available for comment.

Federal cabinet ministers were also meeting Monday to consider ways to end the strike, the Canadian Press reported.

Labour Minister Jean-Pierre Blackburn said a cabinet subcommittee was reviewing "all options," but he wouldn't say whether back-to-work legislation is on the table.

Meanwhile, about 600 CN managers were filling in for the striking workers and losing the battle to keep freight moving at normal rates. Some factories have cut production and sent employees home because of problems caused by the strike.

Lobby group says strike is having widespread impact

A business lobby group, the Canadian Manufacturers & Exporters, said the impact was widespread because many companies no longer stockpile parts and material, preferring what is called just-in-time delivery.

Some lumber companies had piles of product ready to go with no way to move it, and the governor of Maine said his state was short of propane because of the strike, the CBC's Jeannie Lee reported.

Nova Chemical Corp., an Alberta enterprise now run from Calgary and Pittsburgh, said production was running an average of about 15 per cent below normal at its plants in Eastern and Western Canada because of the strike.

Greg Wilkinson, a Nova vice-president, said companies that buy plastics and chemicals from Nova may have even bigger problems.

"Our customers right now are facing pressure in terms of supply and so we are working closely with CN to try to identify priorities, which customers are closest to shutting down," he told CBC News Online.

With files from the Canadian Press