Powerful Quebec union head Michel Arsenault said seasonal workers in the province's rural areas will be particularly hard hit by the changes.
"We're going to continue to put pressure on the federal government," Arsenault said at a rally in downtown Montreal.
"We want to mobilize the whole Quebec population."
Protests were held in several other cities across the province, including Laval, Quebec City, and Sherbrooke. There were also demonstrations in Ottawa and New Brunswick.
Human Resources Minister Diane Finley announced major EI reforms last May that are now being phased in.
The changes include an expectation that claimants accept any job for which they're qualified, within 100 kilometres of their home, as long as the pay is 70 per cent of their previous salary.
They must also prove they're actively seeking work.
Detractors of the plan say it unfairly targets Atlantic Canada and Quebec, where there are a number of seasonal industries such as forestry and fishing.
Finley issued a statement this week downplaying concerns, repeating that nobody will lose any benefits as long as they try to find a job and accept a reasonable offer of employment.
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