The government has issued an ultimatum saying the two sides need to come to an agreement or back-to-work legislation will ensue. Here's an excellent article on that topic with some historical background:
http://www.cbc.ca/news/canada/story/2011/06/15/f-faq-back-to-work-legislation.html
Here a columnist asks what's the hurry:
http://www.theglobeandmail.com/news/opinions/editorials/why-the-rush-to-end-the-air-canada-and-canada-post-strikes/article2062414/
