A new poll has raised the stakes for Premier John Horgan and B.C. Liberal Leader Andrew Wilkinson prepare for a debate tonight.

Horgan will argue in favour of proportional representation and Wilkinson will advocate for first past the post on television and radio.

This comes as Mainstreet Research has declared that there's a "dead heat" among 616 respondents to its latest poll.

A bare majority—50.5 percent—say they will vote in favour of retaining first past the post. Nearly as many, 49.5 percent, stated that they prefer a proportional representation system.

There are three options for PR on the ballot, which must be mailed to Elections B.C. by November 30.

Mainstreet's poll found that 62 percent of those between 18 and 34 support proportional representation, whereas the same percentage over 65 say they are in favour of first past the post.

The poll also found that among decided and leaning voters, the B.C. Liberals enjoy a small lead over the NDP, with 33.9 percent support compared to 32.3 percent.

The B.C. Greens are in third place at 18.2 percent.

"The slight dip for the NDP is likely due to an uptick of support for the Greens," Mainstreet CEO Quito Maggi said in a news release. "That said, the NDP and the B.C. Liberals remain in a statistical tie."