TORONTO -- Support for Justin Trudeau among young voters appears to have plummeted in the wake of the Liberal leader’s meeting with teenage environmental activist Greta Thunberg and the release of his party’s platform.

Polling data from Nanos Research shows that the proportion of voters aged 18 to 29 who cite Trudeau as their preferred prime minister fell from nearly 35 per cent to a little more than 24 per cent within 24 hours.

“If you’re a Liberal, you’ve got to be very nervous,” pollster Nik Nanos said Monday on CTV’s Trend Line podcast.

The poll, which was commissioned by CTV News and The Globe and Mail and based on data collected between Sept. 27 and Sept. 29, found no clear beneficiary to the drop in youth support for Trudeau.

Conservative Leader Andrew Scheer, Green Party Leader Elizabeth May and People’s Party Leader Maxime Bernier all saw slight increases in their support in this category, while the number of respondents saying they were unsure rose by four percentage points. NDP Leader Jagmeet Singh saw a decline in youth support of about one-eighth of a percentage point between Sept. 28 and Sept. 29, but had an overall increase of 5.6 percentage points over the full three days of polling.

“I think we’re going to call this the Greta Thunberg effect,” Nanos said.

Despite the drop, Trudeau’s youth popularity remains higher than it did in the days immediately following the release of images showing him in blackface and brownface.

THUNBERG, TRUDEAU AND SCHEER

The Liberal leader met with Thunberg on Friday while the prominent activist was in Montreal for a climate-change march that was attended by hundreds of thousands of people.

The 16-year-old Swede took Trudeau to task, telling him he wasn’t doing enough to fight climate change. Though that is her standard message for any world leader, Nanos said he still saw it as a risk for Trudeau to agree to the meeting.

“What’s it like to have Greta Thunberg tell the prime minister … ‘You’re not doing enough?’” he said.

Scheer attracted plenty of criticism online for staying away from the march in Montreal. According to Nanos, this did not result in a drop in his popularity.

“The fact of the matter is that you know Andrew Scheer is not going to win the election based on his environmental platform,” Nanos said.

“If he does win the election, he’s going to win it based on his focus on the middle class and the cost of living and people not being happy with Justin Trudeau.”

Before the campaign began, Nanos found that the environment – including both a desire to mitigate the effects of climate change and a wish to scrap the federal carbon tax – was the most important single campaign issue for voters.

THE BIGGER PICTURE

Combining all age groups, the gap between Trudeau’s personal popularity and Scheer’s is now the smallest it has been since the campaign began.

Nanos registered support for Trudeau as preferred prime minister as 28.26 per cent, compared to 27.99 per cent for Scheer. Another 18 per cent of voters are undecided on this score.

The two had been nearly six percentage points apart a few days earlier, on Sept. 25.

“As long as the focus continues to be on the Liberals and specifically on Justin Trudeau, it’s just not going to be good for them,” Nanos said.

When looking at party preference, the Conservatives retain a slim lead with 34.04 per cent support, versus 32.74 per cent for the Liberals.

For most of the campaign, the gap between the two parties has been within the 2.8-percentage-point margin of error, leaving them in a statistical tie.

‘DOUBLE HORSE RACE’

While those two parties appear to be battling to win the most seats on Oct. 21, another fight is underway further down in the polls.

The NDP are polling at 13.18 per cent and the Greens at 12.63 per cent, likely bringing the two parties into fierce competition.

“It’s like a double horse race … the horse race to win and the horse race to place third,” Nanos said.

The Greens have been hovering around 13 per cent for several days now – their highest level ever, and approximately double the support they were pulling during the early days of the campaign.

“The last week has been very good for the Green Party,” Nanos said.

Rounding out the latest Nanos polling data, the Bloc Quebecois have support from 4.11 per cent of voters and the People’s Party are the preferred option for 2.54 per cent.

METHODOLOGY

The Nightly Nanos Election Tracking is produced by Nanos Research, CTV News and the Globe and Mail. The data is based on dual frame (land + cell-lines) random telephone interviews using live agents of 1,200 Canadians using a three night rolling average of 400 respondents each evening, 18 years of age and over.

The random sample of 1,200 respondents may be weighted by age and gender using the latest census information for Canada. The interviews are compiled into a three night rolling average of 1,200 interviews, where each evening the oldest group of 400 interviews is dropped and a new group of 400 interviews is added.

A random telephone survey of 1,200 Canadians is accurate ±2.8 percentage points, plus or minus, 19 times out of 20.