Two celebrated authors and former journalists will be going head-to-head as the NDP and Liberal candidates in an upcoming Toronto federal byelection, a race that's expected to preview which of the two opposition parties will likely emerge as the alternative to the Tories in the next national election.

The Liberals picked Chrystia Freeland to fly their banner in the riding of Toronto Centre, while the New Democrats selected Linda McQuaig — both political rookies.

Freeland, who came under fire from McQuaig before her victory was even announced, wouldn't take the bait, saying only that she was looking forward to the race and the chance to defeat the governing Conservatives in the 2015 general election.

Canada's at a tipping point, she said. The economy is changing and only the "companies and the people who figure that out who grasped that this is a consequential moment, are going to make it," she said after her victory speech.

"Canadians are ready for a change," Freeland said. "They've had some time with the Harper government and they're not too happy with where they've gotten."

McQuaig quickly shifted into byelection mode after her first-ballot victory, putting both Freeland and Prime Minister Stephen Harper's Conservatives in her crosshairs.

'Post-Harper era'

Canada is moving into the "post-Harper era," she said in her victory speech, eliciting a roar from the crowd of party faithful.

The Tories are on the ropes from the Senate scandals, she said, and the outcome of the Toronto byelection will shape the direction of the next national election in 2015.

Liberals nominate candidate for federal byelection in Toronto Centre

Liberals met Sunday to choose their candidate. The NDP first set Sept. 15 as the date for their nomination contest. (CBC)

She called Freeland Liberal Leader Justin Trudeau's "hand-picked choice" who thinks nothing can be done about income inequality, a big issue in a riding that includes low-income neighbourhoods as well as some of the most expensive homes in the city.

But it will be at the forefront of the NDP's campaign, she promised.

"The Liberals, sadly, have a terrible track record of sounding progressive and then, when they get into office, they tend to just kind of consolidate whatever the Conservatives have done before them," McQuaig said.

"And I think we're seeing that same pattern unfold here."

Freeland, who was born in Alberta, beat community organizer Todd Ross and former banker Diana Burke to represent the downtown riding, which the Liberals have held since 1993.

Ross and Burke emphasized their strong local ties in their final pitch to party members, while Freeland, who moved back to Toronto from New York with her family, said she was ready to roll up her sleeves to work for the riding.

Together with Trudeau, the Liberals will craft a "compelling" vision for Canada, she told the party members. The Conservatives have "absolutely no idea" that the country needs a new economic agenda for the 21st century.

"What we are getting from the Harper government is the reheated ideological leftovers of 1990s U.S. Republicanism," said Freeland, who worked as a foreign journalist before becoming editor-at-large for Thomson-Reuters.

"And what is so galling to me is that the Americans who wrote the recipe in the first place, have given up on it because it doesn't work."

Support from high-level Liberals

Freeland has attracted the support of several high-profile Liberals, including former cabinet ministers Bill Graham and Art Eggleton.

Graham, who held the riding for years, said Freeland's economic and business experience will be key in the next general election.

"The Conservatives will run on their economic record," he said. "Justin wants and needs a team that can stand up and say that the Liberal party has always had a better economic record and a better understanding of the economics of this country."

Some experts say the byelection could be a preview of the next election, with both opposition parties facing off as the government-in-waiting.

Harper hasn't yet called the date of the byelection, which was triggered when former interim Liberal leader Bob Rae resigned.