Thousands of people marched in Toronto's annual Labour Day Parade this morning to show their support for local unions.

Among them was federal Opposition Leader Tom Mulcair, who took shots at Prime Minister Stephen Harper and Liberal Leader Justin Trudeau for what he called their shortfalls on the labour file.

Mulcair said it's important to remember what organized labour has brought to Canadian society, including the concept of a weekend, workplace safety and wage equality.

He warned all those rights are "under attack right now," both in Canada and south of the border.

The parade cut through the city's downtown Queen Street and University Avenue to the Canadian National Exhibition.