OTTAWA -- Transport Minister Marc Garneau issued a pointed warning Thursday to all airlines operating in Canada: forcibly removing passengers from overbooked airplanes will not be tolerated.

Garneau sent a letter to every airline that flies in and out of the country to warn that an incident like the one that injured an American doctor in Chicago earlier this week is not to happen in Canada.

"I am sure that you were as disturbed as I was, and as all Canadians were, over the appalling incident that took place on-board a United flight earlier this week, when a passenger was forcibly removed from his seat," he wrote.

"I am writing to you today to convey that such an incident would be unacceptable in Canada."

The warning goes out not just to Canadian airlines such as Air Canada and WestJet, but also to international airlines that fly in and out of the country -- which includes United Airlines.

The letter comes five days after David Dao, 69, was dragged off a United flight after refusing to leave his seat to accommodate airline crew members. He suffered a concussion, a broken nose and two missing teeth when security officers forced him off the plane against his will, banging his head on armrests in the process.

Dao spent almost five days in hospital and requires reconstructive surgery on his sinus. His lawyers told a news conference Thursday they expect to sue the airline.

The incident spawned outrage from already frazzled airline passengers. United CEO Oscar Munoz compounded the blowback when he initially appeared to blame Dao for the incident, accusing him of being belligerent and unco-operative.

Munoz has since called Dao directly to apologize and issued a notice to United employees that passengers must not be forced off airplanes except for security reasons.

Passenger rights advocate Gabor Lukacs said the warning from Garneau is meaningless because there is nothing the government can do if the airlines don't comply.

"The reality is if this were to happen in Canada there would be no recourse," said Lukacs.

Westjet Airlines spokeswoman Lauren Stewart acknowledged the company received Garneau's letter and following it would not be an issue.

"As a policy, WestJet does not deliberately overbook our flights," she said in an email.

Air Canada spokesman Peter Fitzpatrick said his airline co-operates with the government "on all matters."

"With respect to over sales, it is important to note we are very conservative in our approach so it is rare that a flight is overbooked," Fitzpatrick said. "In these instances we usually find volunteers to travel on the next flight and any decisions are made before final seats are assigned and customers board the aircraft."

Air Canada and United codeshare flights, but are separate companies with different policies. United's current board chair Robert Milton, used to be the CEO of Air Canada.

Garneau's warning comes ahead of expected legislation to introduce a passengers' bill of rights. The legislation, due this spring, is to outline what passengers can expect from airlines in situations such as bumping from overbooked planes or for lost or damaged luggage.

"When passengers purchase an airline ticket, they expect and deserve that the airline will fulfil its part of the transaction," Garneau wrote.

"When that agreement is not fulfilled, passengers are entitled to clear, transparent and enforceable compensation."

Lukacs said he is skeptical the new legislation will be more than window dressing unless there are new directives and policies by the Canadian Transportation Agency to enforce them.