09/07/2015 04:06 EDT | Updated 09/07/2016 01:12 EDT

Federal party leaders to spend Labour Day in vote laden Toronto area.

OTTAWA — The political party leaders are anything but idle this Labour Day as they kick off the next round of the federal election campaign marathon.

The three major party leaders are spending the day in what is viewed as the biggest battleground, the Greater Toronto Area.

New Democrat leader Tom Mulcair will rally a key component of his party's base, organized labour.

He'll take in Toronto's annual Labour Day Parade after speaking to members of Unifor — Canada's largest private sector union.

Stephen Harper and Justin Trudeau will also chase votes in the GTA.

Harper has campaign events in east Toronto and Mississauga while Trudeau also has a scheduled event in Mississauga.

Trudeau will later fly to Prince Edward Island for an evening campaign event in Summerside, which has been a thorn in the side of PEI Liberals.

Summerside is the federal Conservatives' only foothold on PEI, part of the riding of Egmont that has been held by Fisheries Minister Gail Shea — the other three ridings in the province are controlled by the Liberals.

Bloc Quebecois leader Gilles Duceppe is attending a party event in Montreal while Green Party leader Elizabeth May is campaigning in her Vancouver Island riding.

The Canadian Press