The union for 10,000 striking Air Canada flight attendants said Monday they won’t return to work even though the strike, now in its third day, has been declared illegal. The strike at Canada’s largest airline is affecting about 130,000 travelers a day at the peak of the summer travel season, and the two sides remain far apart on pay and other issues.

Air Canada said rolling cancelations now extend to Tuesday afternoon after the union defied a second return-to-work order. The airline said earlier said operations would resume Monday evening but the union president said that won't happen.

The Canada Industrial Relations Board had declared the strike illegal earlier on Monday and ordered the striking flight attendants back on the job. But the union said it will defy this second return to work order, after an earlier one had been ignored. The earlier one also ordered the union to submit to arbitration.

The board, an independent administrative tribunal that interprets and applies Canada’s labor laws, had said the union needed to provide written notice to all of its members by noon Monday that they must resume their duties.