FREDERICTON -- All three Green members of the New Brunswick legislature say they'll vote in favour of the Liberals' throne speech Friday, offering Premier Brian Gallant a dim glimmer of hope that his minority government could survive at least a bit longer.

Gallant still needs one more opposition member to support his government to survive the confidence vote, and Progressive Conservative Leader Blaine Higgs said he is confident the Liberals will be defeated.

"I still remain optimistic, but I'm not here for the goodness of my health ... we've got to make some decisions that matter," he said.

The governing Liberals won just 21 seats in the September election -- one fewer than the Tories -- while the Greens and People's Alliance each won three seats.

The Greens' announcement appears to leave the government's fate up to the three People's Alliance members.

Leader Kris Austin said the trio would be voting as a block, but wouldn't say Thursday how they'll vote. His party had previously said it would provide stability to a Tory government for up to 18 months.

If the Liberals lose a confidence vote, it's expected the lieutenant-governor would ask the Tories to try to form government.

Gallant said Thursday that if he loses the vote, the Liberals will step aside.

"I'll resign the government. I've made it clear that I don't think New Brunswickers want an election. And frankly if we were to go into an election we would be rebuking the very strong message sent to us on election night. People have sent a minority government to Fredericton for a reason," he said.

If he loses, Gallant said he would have a conversation with his wife to decide if he stays on as opposition leader, or quits.

Gallant will have one last chance to make his case when he closes debate on the throne speech Friday morning, before the vote is held.

Despite the indication of their vote, Green members weren't giving the Liberal government any glowing endorsements in the legislature Thursday.

Leader David Coon said over the last four years he has lost confidence in the government and its leadership.

"The political meddling in the work of the legislature, the neglect of our health, child protection and senior care systems, and of the poor, the firing of our chief medical officer of health and the dismantling of her office, the handing over of extramural to Medavie, the inaction on renewable energy and climate change, and the degradation of our forests have all left our province worse off," Coon said.

But he didn't have a glowing review of the Tories either.

"I have little confidence that they have changed, and recent comments on fracking, language rights, Indigenous people and climate change have only confirmed this to me," Coon said.

However he said the amended Liberal throne speech, which contains some items from the Green platform, could be advanced for the benefit of their constituents, and all New Brunswickers.

Gallant said he's hoping opposition members will decide to put politics aside and base their decision on the actual throne speech.

"If they do that, and they base their vote on the contents of the speech from the throne, I feel like we can gain the confidence of the house," he said.

Gallant said if he continues to govern, then he knows he will have to do better by working more collaboratively with the other parties.