Two Toronto groups are exhorting Canadian workers to call in sick en masse next Tuesday, on May Day, as a protest against "the attacks of the one per cent."

Members of the groups wearing yellow smiley-face masks unfurled a nine-metre-wide banner Tuesday morning from a bridge over Toronto's Gardiner Expressway, telling motorists that next Tuesday, observed in dozens of countries as a workers' holiday, is "a good day to be sick."

An accompanying news release says "people are suffering with Harperitis and have serious headaches from Fordotrophy," referring to right-wing Toronto mayor Rob Ford, "which makes it really hard to work and make a living. They should call in sick on May 1…. A nice day in the sun will help."

'Rumours have also surfaced that multiple washroom breaks might soon also be declared illegal'—Groups calling for mass sick day

The release goes on to discuss the benefits of sunlight as a source of Vitamin D.

The stunt was somewhat tongue-in-cheek, Occupy Toronto organizer Lana Goldberg said.

"I mean, partially it was an attempt to get some attention, but also it does seem like people are sick and fed up with the austerity agenda," she said. "This would be a good day to take off work and show the government that we are not happy with the way things are going."

Some Air Canada pilots have done just that at least three times over the last five weeks, the airline says, as part of a bitter labour dispute over salaries and pensions. Most recently, 150 pilots — two to three times the typical rate, according to Air Canada — called in sick on April 13. The Canadian Industrial Relations Board ruled it an illegal strike, and pilots who participated as part of a work stoppage could face fines up to $1,000 a day.

In the wake of that ruling, "it is unclear whether calling in sick is still legal in Canada," the news release from Occupy Toronto and the migrant-advocacy group No One Is Illegal says. "Rumours have also surfaced that multiple washroom breaks might soon also be declared illegal."

May 1, or May Day, is celebrated as Labour Day in about 80 countries. In Canada and the United States, where Labour Day is in early September, movements have campaigned for decades to make May 1 an official holiday.

Goldberg said 115 cities across North America will hold May Day rallies this year. In Europe, rallies routinely draw hundreds of thousands of marchers.