Unionized workers at Canada’s Ekati diamond mine may go on strike on March 29, 2006 if BHP Billiton does not return quickly to the bargaining table, according to a report by Reuters.%%The union, the Public Service Alliance of Canada, which represents about 400 employees or 60% of the diamond mines work force, served BHP Billiton with a strike notice late on Monday. The notice came about a week after union members voted against a labor contract offer from the company.%%BHP then said it would not return to the bargaining table earlier than April 18, 2006. BHP, based in London and Melbourne, would not comment on the negotiations but said there was a contingency plan in place should a strike occur.