OTTAWA - Federal politicians worked late into the night to debate a back-to-work bill to send a pair of Air Canada labour disputes to binding arbitration in order to keep the airline flying.

Bill C-33, which passed 155-124 at about 1:30 a.m. ET Wednesday, covers about 8,600 mechanics, baggage handlers and other ground crew at Air Canada (TSX:AC.B) and about 3,000 pilots.

Labour Minister Lisa Raitt had proposed the back-to-work legislation on Monday, saying a work stoppage at Air Canada was something the country could not afford. The government had invoked closure on Tuesday afternoon, setting up the final vote in the House of Commons.

But the union representing the mechanics and other workers said Tuesday that the decision to impose arbitration on its talks with the airline eroded labour rights.

International Association of Machinists and Aerospace Workers executive Dave Ritchie said the bill would ”poison labour relations across Canada.”

Under the “final offer selection” arbitration process, the union and airline will both put forward their best offer and an arbitrator will select one.

The bill now goes to the Senate, where the Conservatives are expected to use their majority for speedy passage. The legislation could receive royal assent before the end of the week.

The pilots’ union and the machinists are the last two groups with which Air Canada needs to reach an agreement.

Flights at Air Canada were set to stop this week after the airline said it would lock out its pilots and the machinists union said it would strike in the midst of the key March Break period.

However Raitt stepped in and blocked a work stoppage by referring the matter to the Canada Industrial Relations Board.<

Last September, the airline reached a deal with its flight attendants after a strike vote prompted Raitt to intervene.

And a walkout by the airline’s customer service agents represented by the Canadian Auto Workers lasted just three days last year after Raitt threatened a back-to-work bill.

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• Labour Day: A Canadian Invention

  Few Canadians realize it, but Labour Day is as Canadian as maple bacon. It all began in 1872, when the Toronto Typographical Union went on strike to demand a nine-hour workday. When <i>Globe and Mail</i> chief George Brown had the protest organizers arrested, Prime Minister John A. Macdonald passed a law legalizing labour unions. Thus, a Conservative prime minister became a hero to the working class, and Canada became among the first countries to limit the workday, doing so decades before the U.S. The typographers' marches became an annual event, eventually being adopted by the U.S., becoming the modern day Labour Day.

• The Winnipeg General Strike

  The end of World War I brought social instability and economic volatility to Canada. On May 15, 1919, numerous umbrella union groups went out on strike in Winnipeg, grinding the city to a halt. Protesters were attacked in the media with epithets such as "Bolshevik" and "Bohunk," but resistance from the media and government only strengthened the movement. In June, the mayor ordered the Mounties to ride into the protest, prompting violent clashes and the death of two protesters. After protest leaders were arrested, organizers called off the strike. But the federal mediator ended up ruling in favour of the protesters, establishing the Winnipeg General Strike as the most important strike in Canadian history, and a precursor to the country's modern labour movement.

• The Regina Riot

  During the Great Depression, the only way for a single male Canadian to get government assistance was to join "relief camps" -- make-work projects set up by the federal government out of concern idle young men were a threat to the nation. The relief camps, with their poor work conditions, became breeding grounds for communists and other radicals. The "On-To-Ottawa Trek" was organized as a protest that would move from Vancouver across the country to Ottawa, to bring workers' grievances to the prime minister. The trek halted in Regina when Prime Minister R.B. Bennett promised to talk to protest organizers. When talks broke down, the RCMP refused to allow the protesters to leave Regina and head for Ottawa, and on June 26, 1935, RCMP riot officers attacked a crowd of protesters. More than 100 people were arrested and two killed -- one protester and one officer.

• Bloody Sunday

  In May, 1938, unemployed men led by communist organizers occupied a post office and art gallery in downtown Vancouver, protesting over poor work conditions at government-run Depression-era "relief camps." In June, the RCMP moved in to clear out the occupiers, using tear gas inside the post office. The protesters inside smashed windows for air and armed themselves with whatever was available. Forty-two people, including five officers, were injured. When word spread of the evacuation, sympathizers marched through the city's East End, smashing store windows. Further protests against "police terror" would be held in the weeks to come.

• Giant Mine Bombing

  In 1992, workers at Royal Oak Mines' Giant Mine in the Northwest Territories went on strike. On September 18, a bomb exploded in a mineshaft deep underground, killing nine replacement workers. Mine worker Roger Warren was convicted of nine counts of second-degree murder. The Giant Mine closed in 2004.

• The Toronto G20

  The Canadian Labour Congress, representing numerous labour groups, participated in protests in Toronto during the G20 summit in June, 2010. When a handful of "Black Block" anarchists rioted through the city core, it brought an overwhelming police response that resulted in the largest mass arrests in Canadian history. More than 1,000 people were arrested, with most never charged with any crime. Numerous allegations of police brutality have been made, and the Toronto police are now the target of several multi-million dollar lawsuits. So far, two police officers have been charged with crimes relating to G20 policing, and charges against other police officers are also possible.

• Occupy Canada

  When Vancouver-based magazine Adbusters suggested the public "occupy Wall Street" to protest corporate malfeasance, New Yorkers took the suggestion seriously, and occupied Zuccotti Park in Manhattan. Canadians followed suit, sparking copycat occupations in all major Canadian cities in September, 2011. By December, most of the occupations had been cleared, all of them non-violently. Though the protests achieved no specific goals, they did change the political conversation in North America. What their long-term legacy will be remains to be seen.