OTTAWA -- Just watch him.

Ready or not, a Trudeau is returning to 24 Sussex Drive, completing the first father-son dynasty in Canada's federal government history.

Justin Trudeau, 43, will become Canada's next prime minister after his party steamrolled to a stunning majority victory Monday night following the longest and most expensive general election in modern times.

The Liberal party, which was en route to claiming more than 180 seats in newly expanded 338-seat House of Commons, becomes the first ever to vault directly from third party status to government.

And Trudeau returns to his childhood home at 24 Sussex Drive, where he was the first-born of Pierre Elliott Trudeau, who served as prime minister for almost 16 years before retiring in 1984.

Trudeau, who became Liberal leader in 2013, faced more than two years of Conservative attack ads before defeating Harper, including a barrage of "just not ready" ads that were so ubiquitous that school-age children could recite them.

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 re-make.

With the magnitude of the Conservative party loss still sinking in, the Conservative leader -- who called the extraordinarily long, 78-day election on Aug. 2 after almost 10 years in power -- is expected to step down as party leader.

And NDP Leader Tom Mulcair, who'd aspired to lead Canada's first NDP federal government, instead lost the party's hard-won 2011 grip on official Opposition status, but managed to hold on to his Montreal seat despite a tough Liberal challenge.

Green Leader Elizabeth May was also re-elected on Vancouver Island.

The New Democrats were decimated, dropping below 40 seats after entering the election with 95. Mulcair had a tough fight just hanging on to his own Montreal seat.

The campaign, which began on a sweltering August long weekend with the country firmly Conservative blue, ended under a threat of October frost and a Liberal red tide.

The shocking Liberal onslaught opened on the East Coast, where Liberals were on track for a remarkable sweep of all 32 Atlantic Canada seats, before rolling into Quebec and Ontario and Manitoba.

With the polls simultaneously closing from the Quebec-New Brunswick border all the way to the foothills of the Rocky Mountains, the scale of the Liberal charge became clear as the ballot counting commenced: The Liberals had more than 40 per cent of the popular vote and were knocking off Conservative and NDP heavyweights across the country.

Trudeau romped to victory in his gritty Montreal riding of Papineau as the Liberals restored their Quebec fortunes to help anchor the surprising victory.

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.

NDP stars including deputy leader Megan Leslie and foreign affairs critic Paul Dewar also fell to Liberal challengers. Olivia Chow -- her late husband, Jack Layton, led the NDP's so-called "orange crush" in 2011 -- succumbed to Liberal juggernaut Adam Vaughan in downtown Toronto.

"I congratulated Mr. Trudeau on his exceptional achievement both for him and his party," Mulcair said in a concession speech in Montreal.

"In this campaign, Mr. Trudeau made ambitious commitments to Canadians and Canadians will have high expectations for their next Parliament."

Harper called the extraordinarily long, 78-day election on Aug. 2 hoping to become the first prime minister since Sir Wilfrid Laurier in 1908 to win four consecutive mandates. However with all opposition parties vowing not to work with him after Monday's election, it was apparent that only a very strong Conservative minority or a Tory majority would keep Harper on as prime minister.

It became apparent early on Monday that it was not to be.

For the 2015 election, there was no longer a blackout on transmitting voting results while polls were still open in other parts of the country -- a ban that had become impossible to enforce in the age of the Internet.

The Conservatives held 159 seats in the 308-seat House of Commons, the NDP had 95 and the Liberals held just 36, with another 18 seats either vacant, held by Independents or shared between the Green party (two seats) and the Bloc Quebecois and a splinter group.

Due to population growth, 30 new seats have been added this election, including 15 in Ontario, six each for Alberta and British Columbia and three more for Quebec.

The Liberals were expected to do well in Atlantic Canada but their remarkable sweep presaged a huge night for the party.

Some 3.6 million Canadians cast ballots during the four-day advance polling period on the Thanksgiving long weekend -- an increase of 71 per cent over the 2011 election, when only three days of advance polls were held.

That increased turnout carried into the main event, with long lines at polling stations in many parts of the country. Just 61.4 per cent of eligible electors cast a ballot in 2011, up marginally from the 58.8 per cent in 2008 -- the lowest ever in a federal election.

There were reports of voters with face coverings -- including skeleton masks and even a pumpkin -- at polling stations, an apparent reaction to the controversy over whether women should be permitted to wear a niqab at citizenship ceremonies.

A face covering is permitted at the polls if the voter swears an oath attesting to their status as an elector and shows the required identification, said Babin Dufresne.

Assembly of First Nations national chief Perry Bellegarde -- who initially said he wouldn't vote in order to maintain his neutrality, then changed his mind -- tweeted about his trip to the polls.

-- With files from Murray Brewster, Jim Bronskill, Jennifer Ditchburn, Bill Graveland and Chinta Puxley