The federal Liberals are riding a wave of popularity, according to a new Nanos poll, with the party showing gains in B.C., Quebec and among Canadians over 60 years of age.

According to results of the weekly Nanos Party Power Index, 58.5 per cent of Canadians would consider voting for the Liberals, which is a 12-month high for the party. The NDP is in second place with 45.1 per cent, while the Conservatives have 40.2 per cent and 27.8 per cent would consider voting for the Green Party.

The Liberals also gained strength on the “Canada Party Power Index,” which considers first and second vote preferences; whether the respondent would consider voting for the party; first and second preferences for prime minister; and whether the respondent believes the current leader has the quality to be a good leader.

This week, the Liberals stand at 59.1 points out of 100, which is a new 12-month high, followed by the Conservatives at 48.4 points, the NDP at 47.6 points, and the Green Party at 30.7 points.

Nik Nanos, president of Nanos Research, said it was a good summer for Trudeau.

“He has cruised through the barbecue circuit and is trending up, even though he hasn’t put a lot in the window on the public policy front,” Nanos said on CTV’s Power Play.

When asked about preferred prime minister, 34 per cent of those surveyed said Justin Trudeau is their preferred choice for Canada’s next prime minister, which is a 12-month high for the Liberal leader.

Prime Minister Stephen Harper is trailing behind with 27.7 per cent of support, while NDP Leader Thomas Mulcair is at 16.9 per cent, and Green Party Leader Elizabeth May holds 4.8 per cent.

But despite it being “pretty clear” that Canadians are favouring Trudeau, Nanos said those numbers could change closer to election time.

“The reality is, when you don’t put out platform ideas, there is nothing -- absolutely nothing -- to repel voters,” he said. “In a way, this is almost an artificial honeymoon. Harper is basically shadowboxing with Justin Trudeau, there’s no policies or platform for him to take a punch at.”

The latest Nanos data is based on random phone interviews with 1,000 Canadians, using a four-week rolling average of 250 respondents each week.

The random telephone survey is accurate within 3.1 percentage points, 19 times out of 20.