Thomas Mulcair's New Democrats continue to lead in national voting intentions and have the inside track on winning the most seats, thanks to wide leads in British Columbia and Quebec and a tight three-way battle in Ontario.

But the Conservatives could be seeing their numbers rebound after hitting a recent nadir.

The New Democrats hold the lead in polls with 32.1 per cent support, compared to 29 per cent for the Conservatives and 27.1 per cent for the Liberals. The NDP has been holding steady in the polls, and has led or been tied for the lead in each of the last 11 national surveys. The Liberals, who appeared to be poised for a rebound of their own a few weeks ago, have plateaued.

Instead, it has been the Conservatives who have seen their support levels improve. After placing third or tied for second in five of seven polls, the Tories have placed second or tied for first in the last two.

If an election were held today, the New Democrats would likely win between 113 and 135 seats, with the Conservatives winning between 102 and 139 seats. The Liberals would likely take between 74 and 106 seats.

The Bloc Québécois, at 5.5 per cent, would likely capture between one and four seats, while the Greens, at 4.9 per cent, would take one.

These are the latest estimates from today's launch of the CBC Poll Tracker. The Poll Tracker, which will be updated continuously as new polls are published between now and the expected October election, is an interactive feature that will follow the evolution of polling trends and likely seat outcomes over the next three months.

CBC's Poll Tracker, based on Eric Grenier's polling averages and analysis, launches today.

The Poll Tracker's estimates are based on the methodology used at ThreeHundredEight.com since the site's launch in 2008.

Read a short introduction on how to use the Poll Tracker — or check out the Poll Tracker to see the polling averages and data going back to the beginning of 2015 as well as how the latest seat projections break down at the regional level.

NDP's three pillars for minority government

Though the seat projection overlaps significantly between the New Democrats and Conservatives, the NDP is narrowly favoured in the average projection at 127 seats to 119 for the Conservatives. This edge is largely due to the New Democrats' strong showing in British Columbia, Quebec and Ontario.

The NDP leads in the polls in B.C. with 38.6 per cent support, compared to 26.4 per cent for the second-place Conservatives. That is enough to give the NDP as many as 23 seats in the province, almost double the number the party won in 2011.

In Quebec, the NDP leads with 33.7 per cent support, followed by the Liberals at 23.3 per cent. With these numbers, the New Democrats could take 52 seats — slightly less than the 59 seats the party won in 2011, when it received 42.9 per cent of the vote.

The race is much different in Ontario, where the three main parties are locked in a virtual tie. The Conservatives narrowly lead in Canada's largest province, with 32.1 per cent compared to 31.2 per cent support for the Liberals. The NDP have a 30.4 per cent share, giving them the chance to win 31 seats, nine more than in 2011.

But the race in Ontario keeps getting closer and closer. On June 15, 4.9 points separated the first-place Conservatives from the third-place NDP. That gap has decreased in every subsequent week to now sit at just 1.7 points.

Favourable trends for NDP

Ontario is rare, however, in being one of the battleground provinces where voting intentions appear to be in flux. Polling levels have been steady for the last few weeks in most other parts of the country.

The Prairies and Atlantic Canada are two exceptions. In Saskatchewan and Manitoba, the NDP has surpassed the Liberals in recent weeks to move within nine points of the leading Conservatives. As recently as mid-June, the NDP had been in a tie with the Liberals for second place. Now, the party holds an edge of almost four points over third place. This uptick could deliver as many as eight seats to the NDP, a big improvement over the two the party won in these two provinces in 2011.

The trends are also not looking positive for the Liberals in Atlantic Canada, where they have dropped to 39.5 per cent. That is a slip of six points since the middle of May, all of which has apparently gone to the NDP. With the Conservatives having dropped precipitously in the region since 2011, the Liberals are still well-positioned to win the lion's share of seats — but the former prospect of the NDP being reduced to a few beachheads in Atlantic Canada no longer appears likely.

Nevertheless, the national race remains extremely close. A separation of just five points between the three main parties still puts the campaign on track to be the closest contest in Canadian history.

CBC's Poll Tracker aggregates all publicly released polls, weighing them by sample size, date and the polling firm's accuracy record. Upper and lower ranges are based on how polls have performed in other recent elections. The seat projection model makes individual projections for all ridings in the country, based on regional shifts in support since the 2011 election and taking into account other factors such as incumbency. The projections are subject to the margins of error of the opinion polls included in the model, as well as the unpredictable nature of politics at the riding level. The polls included in the model vary in size, date and method, and have not been individually verified by the CBC. You can read the full methodology here.