The Conservatives are facing a cooler reception from Canadians as they head home for the holidays, with new poll numbers suggesting a significant drop in the party's brand strength in traditional strongholds.

According to the Nanos Party Power Index, the Tories are losing ground to the NDP and Liberals in Ontario and the Prairies — key battlegrounds in the next federal election.  

The number:

54

The Conservatives's Party Power Index score in the Prairies, a drop of 12 points since Parliament returned in October.

Source: Nanos Party Power Weekly Index Tracking, four-week rolling averages of 197 voters in the Prairie provinces ending Dec. 6, 2013 compared to period ending Oct. 18, 2013. Random land- and cell-line sample using live agents, accurate to within 7.1 percentage points, +/- 19 times out of 20.

"Stephen Harper and the Conservatives built their majority and their successful kind of resurgence on the Canadian political field in the West," said Nik Nanos, president and CEO of Nanos Research. "Fast forward through this session — not a great time for the Conservatives."

Nanos Research releases a new Party Power Index score each week. It's a combination of measurements of federal party brands based on questions about the parties and the leaders, scored on a scale between zero to 100 for each party.

In the prairies, Conservatives have dropped 12 points since MPs returned to Parliament on Oct. 16. The Tories maintain the lead with a score of 54, but the Party Power Index shows the Liberals and NDP closing in with scores of 52 and 47, respectively.

Nanos Number: Prairies

Nanos Research looks at December 2013 poll numbers for Prairie province voters

These numbers are based on random telephone (cell and land-line) interviews with 197 voters in the Prairie provinces using a four-week rolling average ending Oct. 18, 2013, and Dec. 6, 2014 and are accurate to within 7.1 percentage points, 19 times out of 20.

"The Tories can't afford to lose more here because, you know what, if the Prairies start to unravel for the Conservatives, it won't be good news in the rest of the country," Nanos told Power & Politics host Evan Solomon.

In Ontario, the Nanos numbers reveal significant gains for the New Democrats. Though they still sit in third place with a score of 48, the NDP have gained six points. In comparison, the Liberals fell six points and the Tories dropped four.

These results are based on random telephone (cell and land-line) interviews with 300 voters in Ontario using a four-week rolling average ending Oct. 18, 2013 and Dec. 6, 2014, accurate to within 5.7 percentage points, 19 times out of 20.

Which leader would make the best prime minister?

The polls also show NDP Leader Thomas Mulcair enjoying a lift from the fall session of Parliament. He's the only leader who has gained favour among Canadians in the past few months, according to the latest Nanos tracking numbers.

On the question of which major party leader would make best prime minister, Stephen Harper and Justin Trudeau are in the lead with close scores of 27 and 26, respectively. However, those scores reflect decreases of four and six points. 

With a score of 20, Mulcair has seen a four-point increase in his personal brand.  

"Two lumps of coal for Harper and Trudeau and a little bit of a Christmas bump for Tom Mulcair coming out of the last session," said Nanos.

These tracking numbers are based on random telephone (cell and land-line) interviews with 1,000 Canadians using a four-week rolling average ending Oct. 18, 2013 and Dec. 6, 2014, accurate to within 3.1 percentage points, 19 times out of 20.

Nik Nanos digs beneath the numbers with CBC News Network's Power & Politics to get to the political, economic and social forces that shape our lives. Recognized as one of Canada's top research experts, Nanos provides numbers-driven counsel to senior executives and major organizations. He leads the analyst team at Nanos, is a Fellow of the Marketing Research and Intelligence Association and a Research Associate Professor with SUNY (Buffalo).

Corrections

  • The story has been edited from an earlier version that, due to an editing error, incorrectly referred to party "support." In fact, the Nanos Party Power Index is based on a combination of measurements from questions about the federal parties and their leaders to gauge the strength of the parties' brands.
    Dec 12, 2013 7:50 AM ET