Note: With this column Éric Grenier, founder of threehundredeight.com, makes his debut as a regular contributor to CBC News.

By this time next year, at the latest, the next federal campaign will be underway. A lot can happen in a year, but to prevail in 2015, parties will need to move the dial from where things stand today.

Or, in the case of Justin Trudeau's Liberal Party, prevent a lead that could deliver them victory from drifting away.

Ever since Trudeau was named leader of the party in April 2013, the Liberals have been the frontrunner in national polls. On average, the party has been ahead for 17 consecutive months, and have led or been tied for the lead in 58 of the 63 national polls published since Trudeau's leadership triumph.

Additionally, as the House of Commons reconvenes today, the Liberals appear to be on a mini-upswing. They have registered between 35 and 41 per cent support in polls conducted over the last two months, compared to a range of between 30 and 36 per cent, with the exception of one anomalous poll, over the previous two months.

The governing Conservatives, on the other hand, have not lagged in second place in national voting intentions this long since before Stephen Harper's first electoral win in 2006. But the party is starting to show a little life, managing more than 30 per cent support in 11 of the last 15 polls after not scoring above 30 per cent in the prior 19 surveys.

But while the Tories may be making a move, the New Democrats appear to be stagnant.

Their recent numbers have been dragged down somewhat by the last four polls from Forum Research, which have pegged the party under 20 per cent. But the NDP's support otherwise appears to be stuck. With the exception of the last two months, Tom Mulcair's New Democrats have averaged between 23 and 25 per cent support ever since Trudeau took over the Liberals.

In those last two months, it has dropped to 21 and 22 per cent. Is it a real cause of concern for the NDP or a fluke of one pollster's methodology?

Federal voting intention

Rolling three-poll average of national voter intention surveys conducted since January, 2014. (Eric Grenier for CBCnews.ca)

Big swings in Quebec

The key to determining whether the NDP's recent slump is anything real is in Quebec. The New Democrats have trailed the Liberals there in each of the last five polls, including a large-sample CROP online survey conducted in mid-August. The Liberals, meanwhile, have bounded forward. They have averaged 37 per cent in Quebec over the last 10 polls going back to June. In the previous three months, the party was at 32 per cent in the province.

However, the NDP has only shed a few points' worth of support in Quebec. It is the drop of the Bloc Québécois that has opened up a new opportunity for the Liberals. In surveys conducted since Mario Beaulieu unexpectedly became leader of the party in June, the Bloc has averaged just 17 per cent. That is down from 20 per cent in the spring.

And it may be getting worse for the Bloc leader. In light of the departures of two of his MPs, Beaulieu's Bloc has managed just 13 to 15 per cent support in three of the last five polls. That undoubtedly puts the sovereigntist party at its lowest level of support since its founding more than two decades ago.

The Conservatives have been holding relatively steady in Quebec. But the province is the only region of the country where that can be said.

Conservatives losing ground in Ontario

The Tories' numbers in Ontario are particularly problematic. More than any other province, it was Ontario that gave Harper his majority government in 2011. But the party has not averaged more than 35 per cent support in Ontario in any month since Trudeau became Liberal leader; prior to that, the Conservatives had not averaged less than 35 per cent in any one month in four years.

The Liberals, meanwhile, have been estimated at 40 per cent or more in Ontario in six of the last eight polls.

The New Democrats may be in some trouble in Ontario. They have been polling below 20 per cent in most recent polls, while the party had previously averaged more than 20 per cent in every month going back to the 2011 election.

The NDP's fortunes are looking brighter in British Columbia, where each of the three major parties has led in at least one poll over the last three months. But the Liberals have been putting up consistently better numbers, with the Conservatives in second and the NDP a close third.

Still areas of dominance

Might the Prairies be another close contest? The Conservatives still lead in most polls, but are only in the high 30s to low 40s. The Liberals and NDP have both recently scored around 30 per cent, though it does not appear their support is uniform. The Liberals are more competitive in Manitoba, while the NDP has the edge in Saskatchewan.

The Conservatives remain dominant in Alberta, generally polling in the 50 to 60 per cent range, but the Liberals have made significant gains to poll between 20 and 30 per cent, enough to challenge for a handful of seats.

One party is similarly dominant in Atlantic Canada. The Liberals have averaged more than majority support there since the beginning of the year, with the Conservatives and NDP struggling in the low 20s.

But where do things go from here?

The Liberals have led for too long for it to be chalked up to a simple leadership honeymoon. And their numbers may be even improving. That means the Conservatives need to turn the tide, and the New Democrats need to push themselves back into contention.

The Liberals need to prevent either from happening. They have a year to do it.

Note: This article reviews trends in national public opinion surveys. Methodology, sample size and margin of error if one can be stated vary from survey to survey and have not been individually verified. Read more about threehundredeight.com's methodology here.