As negotiations for B.C.'s first large-scale liquefied natural gas export project reach their critical days, NDP leader John Horgan has a message for investors: expect to pay more tax under an NDP government.

Executives of Malaysian state energy company Petronas were in Vancouver Monday for what may be their final visit with B.C. officials before deciding whether to proceed with an $11 billion investment in a pipeline and LNG processing at the Prince Rupert port.

Pacific Northwest LNG is a cornerstone of B.C.'s bid to enter the Asian energy market. The fall legislature session was devoted almost entirely to the emerging industry, setting in place a tax structure, carbon emission rules and a series of agreements with the Nisga'a Nation to enable TransCanada Corp. to build a 900-km pipeline from northeast gas fields to the North Coast.

Horgan said he instructed NDP MLAs to vote in favour of the 3.5 per cent LNG tax that emerged from negotiations with investors, because they need "certainty" to make final investment decisions. The surprise support came after NDP MLAs denounced the tax arrangement as a sellout of provincial resources, leaving Green Party MLA Andrew Weaver and independent MLA Vicki Huntington alone in voting against it.

"If we're going to get to final investment decisions, we need to have a tax framework," Horgan told reporters after the LNG legislation was passed into law. "I believe the framework is inadequate, I've said that, I will say that to the companies when I meet with them, and they should know that when the government changes in 2017, I'm going to be wanting to look at those agreements."

In debate, B.C. Liberal MLAs repeatedly questioned the NDP's professed support for LNG, referring to the party's call for an investigation of hydraulic fracturing that has been conducted in B.C. since the 1960s. And the NDP denounced and opposed the government's move to regulate greenhouse gas "intensity" rather than cap emissions for LNG plants.

Petronas CEO Shamsul Azhar Abbas about the cost of LNG development in B.C. In October, Abbas warned that federal and provincial rules and taxes "threaten the global competitiveness of the Pacific Northwest LNG project."

In his quarterly financial update last week, B.C. Finance Minister Mike de Jong said the low and fluctuating price for natural gas in a shale-gas-rich North American market still indicates the Asia export market is viable.

"The proof of that, of course, will be final investment decisions from proponents," de Jong said.

Horgan on a recent trip to Prince Rupert, where he expressed doubts about Petronas and another LNG proposal for Prince Rupert that has been delayed by lead proponent British Gas Group.

Petronas is leading a consortium that includes Chinese, Japanese, Indian and Brunei investors. Petronas paid $5 billion last year to take over Progress Energy Canada, which has major shale gas holdings in northeast B.C. and Alberta.