Tuesday's election is promising to be a nail-biter, with a new poll pegging support for Christy Clark's Liberals and John Horgan's NDP at a tie going into the vote.

Thirty-eight per cent of respondents in the Insights West poll, conducted from Friday to Monday on behalf of CTV Vancouver, said they'd cast a ballot for the incumbent Liberals if the election were held immediately.

The same percentage said they'd vote for the NDP, followed by 15 per cent who'd opt to throw their support behind Andrew Weaver's Green Party.

The rest said they either hadn't decided or would support one of B.C.'s smaller parties or independent candidates.

The poll results suggest a neck-and-neck race, though there's been some skepticism about the predictive power of polling after the 2013 election, which saw the Liberals win a decisive victory despite the NDP's nine-point lead on the eve of election day.

Despite the uncertainty, NDP campaigners have taken some hope from early voting numbers, which show roughly 615,000 people cast early ballots – nearly a quarter-million more than the early-bird turnout for the last election.

"We're hoping that it signifies a very motivated electorate, and an electorate that is interested in seeing a change in government," party strategist Maria Dobrinskaya told CTV News on Monday.

There were two extra days of advanced polling this round, but the daily average was still higher than it was in 2013.

The Insights West survey also suggests each of the three main party leaders is enjoying positive momentum heading into the vote. Weaver showed the biggest bump in support, with his approval rating jumping from 35 per cent in April up to 46 per cent.

Clark's increase was substantial as well, hiking from 30 to 38 per cent, putting her close behind Horgan, whose approval rating went from 37 to 42 per cent.

Liberal strategist Lorne Mayencourt credited the party leader's response to Donald Trump's softwood tariff – a proposed ban on U.S. coal imports that Prime Minister Justin Trudeau has promised to consider – for her increased popularity.

"Forestry is huge in British Columbia and we said right from the beginning we will use every tool at our disposal to get a softwood agreement and protect B.C. jobs," Mayencourt said. "John has not done that, he's had lots of opportunity to take a stand."

The NDP noted that Horgan has repeatedly pledged to secure a good deal for forestry workers, but that the party has avoided blustering for its own benefit.

"I think Christy Clark is playing a dangerous game, she's using a very serious matter around trade as an election tool," Dobrinksaya said.

"Under this government there's been 30,000 forestry jobs lost, and it's rich for her now to be out there speaking as though she's going to be fighting on behalf of these communities,"

For the poll, Insights West surveyed 801 B.C. adults online, and weighted the data according to Canadian census figures for age and gender. Polls of that size have a margin of error of plus or minus 3.5 percentage points, 19 times out of 20.