Liberal Party Leader Justin Trudeau holds a news conference after asking the Governor General to dissolve Parliament and call an election in Ottawa.
"I am very much looking forward to the three opportunities we'll have during this campaign to debate with the other leaders", Trudeau said at a campaign event on Vancouver Island.
Trudeau is the happy warrior of modern Canadian politics and is a superb campaigner.
"Canada has been a beacon and has tried to lead by example but it's really hard to lead by example when you are Canada and you are by yourself", said Ian Bremmer, president of the Eurasia Group.
Although he swept to victory with his Liberal Party four years ago, a number of controversies have since weakened the Prime Minister's public support.
Scheer has said Trudeau has lied repeatedly about what he did to push former justice minister Jody Wilson-Raybould to offer a negotiated settlement to the Quebec engineering firm, which is facing criminal charges over alleged corrupt dealings in Libya.
Trudeau chose to spend day two of the election campaign in B.C. and Alberta, the latter hostile territory for him when it comes to the topic of oilsand development.
Justin Trudeau fires starting gun for Canada's general election
The leader of the left-leaning New Democrats (NDP), he is the first person of colour to have taken the helm of a major federal political party in Canada.
Last month, a top watchdog ruled the prime minister and his team had indeed breached ethics rules.
Scheer, the head of the conservative party, said Wednesday that Trudeau had lost the moral authority to govern.
Mr Trudeau's challenge is that he is running on his record rather than the uplifting message of hope and change that helped the Liberals attract record numbers of green, youth and aboriginal voters in 2015.
Justin Trudeau began his bid for re-election Wednesday by framing the next 40 days as a time for Canadians to make a choice: whether they want more of his sunny ways or a return to the gloomier days he says are characteristic of life under a Conservative government.
And Green Party leader Elizabeth May was in Victoria, stressing trust in leadership.
He accused Andrew Scheer's Conservatives of having no new ideas, of regurgitating the same "failed" policies of Stephen Harper's previous government, which he described as tax breaks for the wealthy and cuts in services for everyone else, leading to a stalled economy.