The Liberal seven-point advantage continues over the federal election campaign's closing weekend, the latest tracking by Nanos Research for CTV News and the Globe and Mail shows.

According to numbers released on Oct. 18, the day before the election:

The Liberals have 37.3 per cent support nationally

The Conservatives have 30.5 per cent support nationally

The NDP has 22.1 per cent support nationally

The Greens are at 4.7 per cent support nationally

Poll respondents were asked "If a federal election were held today, could you please rank your top two current local voting preferences?"

Compared to a month ago, the responses show the Liberals up six points, the NDP down nine points, and the Conservatives up two points.

Up until the Thanksgiving Weekend, the Liberals and Conservatives were locked in a tight two-way race, pollster Nik Nanos told CTV News Channel on Sunday.

"We saw a two-way race going into Thanksgiving weekend," he said. "But after Thanksgiving weekend, after the pumpkin pie, the Liberals came out … with about a six-point advantage and they've been able to hold onto that advantage in the closing week of the campaign."

According to Nanos Research, the Liberals have benefited from a decline in NDP support over the course of the campaign.

"It took about 66 days for Canadians to figure out who the main challenger would be to (Conservative Leader) Stephen Harper, and it ended up being (Liberal Leader) Justin Trudeau," Nanos said. "The reality is that the NDP, although there's good will toward them, have been squeezed by strategic voters."

Nanos said the shift from NDP to Liberal support can be seen in the two parties' trend lines, which have been mirror images of each other in the last month.

"When the NDP went up, the Liberals went down, and when the Liberals went up, the NDP went down," he said. "So what we've seen is movement from the New Democrats towards the Liberals in order to block Stephen Harper."

Nightly tracking by Nanos Research for CTV News and the Globe and Mail, released Oct. 18.

Low levels of undecided voters

As one of the longest campaigns in Canadian history comes to a close, Nanos said he has been most surprised by the low number of undecided voters leading up to this election.

"On day one of the campaign … undecided was around 12 per cent. Usually at the beginning of the campaign, undecided is around 15 to 20 per cent," Nanos said.

According to the pollster, the early decisiveness was coupled with signals many were unsure which party they would support.

"The interesting thing is that undecided vote was down, but the level of switchers between the New Democrats and the Liberals was exceptionally high. It was at a historic high in terms of the Nanos tracking," he said.

"People were going to get out and vote, but they just weren't sure … whether it would be for the New Democrats or the Liberals. And it looks like, right now, they're looking at the Liberals."

Poll methodology

A national dual - frame (land and cell) random telephone survey is conducted nightly by Nanos Research throughout the campaign using live agents. Each evening a new group of 400 eligible voters are interviewed. An oversample of 800 interviews was conducted on Friday and Saturday.

The daily tracking figures are based on a three-day rolling sample composed of 2,000 interviews. To update the tracking a new day of interviewing is added and the oldest day dropped. The margin of error for a survey of 1,825 decided voters is ±2.3 percentage points, 19 times out of 20.

Larger sample

Today's three-day rolling average is based on 2,000 interviews (800 interviews Saturday, 800 interviews Friday and 400 interviews Thursday).

Full poll at Nanos Research

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