OTTAWA — Justin Trudeau, who confidently guided his Liberal party to a convincing majority victory, now faces several pressing priorities and a raft of longer-term promises.

The immediate issues for the prime minister-designate include a major international conference on climate change, a military mission in the Middle East he has pledged to end and the still-churning refugee crisis enveloping Europe.

On the horizon loom keystone promises from his party's successful campaign: lower taxes for the middle class, the legalization of marijuana, and a slate of democratic reforms including a new electoral system to replace the venerable first-past-the-post regime under which he swept to power.

Trudeau will no doubt be riding an electoral high from the 184 seats the Liberals captured — a whopping 149-riding increase from the last election — but he will already be facing tough questions on how and when he will implement his plan.

Some answers are expected to come at a news conference later today after he addresses party faithful at a rally in Ottawa.

Governments plan to gather in Paris in December for a global summit on climate change. That leaves the Liberals just weeks to come up with a national position based on the party's promise to join with the provinces and territories to take action on climate change, put a price on carbon and reduce carbon pollution.

The Liberals have also committed to ending Canada's combat mission in Iraq against rampaging radical militants — instead focusing Canada's military contribution in the region on the training of local forces, while providing more humanitarian support and immediately welcoming 25,000 more refugees from Syria.

Trudeau has said that the first piece of legislation his government would put forward is one to lower taxes for the middle class and raise taxes for the wealthiest Canadians.

A Liberal government is also committed to revamping the recently enacted omnibus security bill, known as C-51, that gave Canada's spy agency substantial new powers and angered civil libertarians.

Trudeau has also promised the largest new infrastructure investment in Canadian history. The plan would nearly double federal spending on public transit, affordable housing, recreational facilities and other items to almost $125 billion over the next decade.

The Liberal party becomes the first to vault directly from third-party status to government. Even the party's own pollster, who foresaw a majority, hadn't imagined a total so high.

Elections Canada says 68.5 per cent of eligible voters cast ballots, the largest turnout since the 1993 federal election.

Preliminary figures indicate the Liberals captured 39.5 per cent of the vote, the Conservatives 31.9 per cent and the New Democrats 19.7.

Trudeau, 43, completes the first father-son dynasty in Canada's federal government history, as the first-born of Pierre Elliott Trudeau follows in his father's footsteps to 24 Sussex Drive.

Trudeau faced more than two years of Conservative attack ads before defeating Harper, including a barrage of "just not ready" ads so ubiquitous that school-age children could recite them.

Notwithstanding an appeal to Canadians' "better angels" in his victory speech, the Liberal leader made a lengthy denunciation of what he called the politics of division and fear, including a defence of veiled Muslim women who became an unlikely wedge issue during the campaign.

"Canadians have spoken," Trudeau told beaming supporters in his Montreal riding.

"You want a government with a vision and an agenda for this country that is positive and ambitious and hopeful. Well, my friends, I promise you tonight that I will lead that government. … I will be that prime minister."

During the October Crisis of 1970, Pierre Trudeau famously told an inquiring reporter "Just watch me," when asked how far he would go in limiting civil liberties to combat separatist terrorists. The elder Trudeau went on to shape much of the modern Canadian state that Prime Minister Stephen Harper came to power in 2006 in part to remake.

The Conservative leader called the 78-day election, the longest in modern Canadian history, on Aug. 2 after almost 10 years in power. His party will form the official Opposition with 99 seats — 60 fewer than when Parliament was dissolved.

With the magnitude of the loss still sinking in, Harper is stepping down as Conservative leader, according to a statement from party president John Walsh.

"The prime minister indicated that he will continue to sit as a member of Parliament and asks that a process to both select an interim leader and initiate the leadership selection process in our party begin immediately," says the Walsh letter.

Harper, 56, did not announce his resignation in a concession speech to party faithful in Calgary, stating only that the "disappointment you also feel is my responsibility and mine alone."

But he offered gracious congratulations to his younger opponent.

"While tonight's result is certainly not the one we had hoped for, the people are never wrong," said the prime minister, adding he had called Trudeau and "assured him of my full co-operation during the process of transition in the coming days."

Finance Minister Joe Oliver, Immigration Minister Chris Alexander, Fisheries Minister Gail Shea, Veterans Minister Julian Fantino and Aboriginal Affairs Minister Bernard Valcourt were among the Conservative cabinet ministers rejected by voters.

New Democratic Party Leader Tom Mulcair, who had aspired to lead Canada's first NDP federal government, instead dropped to 44 seats from 95 — losing the party's hard-won 2011 grip on official Opposition status.

Mulcair, however, managed to hold on to his Montreal seat.

NDP stars including deputy leader Megan Leslie and foreign affairs critic Paul Dewar fell to Liberal challengers. Olivia Chow, whose late husband Jack Layton led the NDP's so-called "orange crush" four years ago, succumbed to Liberal Adam Vaughan in Toronto.

Green Leader Elizabeth May was re-elected on Vancouver Island but the party lost its only other incumbent — Ontario's Bruce Hyer — and failed to make a long-awaited breakthrough.

Bloc Quebecois Leader Gilles Duceppe went down to defeat, but his party emerged with 10 seats, injecting new life into a party that had almost withered after once holding official Opposition status.

Jim Bronskill, The Canadian Press

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