Travellers hoping for smooth flights this week are facing yet another day of chaos. Air Canada’s flight attendants remain on strike, despite a federal order telling them to get back to work.

The dispute, which kicked off early Saturday, has already seen nearly a thousand flights cancelled and thousands of passengers scrambling to salvage their plans. Air Canada even suspended its financial guidance for the year, a sign of just how disruptive the stoppage has become.

At the heart of the standoff is a battle between Air Canada and the Canadian Union of Public Employees (CUPE), which represents more than 10,000 flight attendants. The Canada Industrial Relations Board ordered them back on the job Sunday afternoon after Labour Minister Patty Hajdu forced both sides into binding arbitration, citing the impact on Canadians and the economy.

But CUPE is pushing back hard. The union has challenged the order in Federal Court, held mass demonstrations at major airports, and accused the government of bowing to Air Canada’s demands. Labour groups across the country are rallying behind the flight attendants, calling the move an “unconstitutional attack on workers’ rights.” Some are even preparing a national “fight back campaign” to support them financially and legally.

For now, travellers are stuck in the middle. Air Canada says flights may resume Monday evening—but only if the strike ends. With both sides dug in, passengers might want to prepare for more turbulence ahead.