VICTORIA - Elections BC is expected to release its preliminary numbers for British Columbia's harmonized sales tax referendum sometime this week, revealing how many people sent in mail-in ballots to decide the fate of the HST.

The results of the long-running battle over the tax won't be announced until late August, so this week's figures will merely provide a chance to read the tea leaves -- what does voter turnout in this provincewide, mail-in referendum suggest?

High turnout would offer a rare encouraging sign for the pro-HST forces in B.C.

Since the referendum was promised last year, opposition to the HST has held a commanding lead in the polls. But the gap has narrowed in recent months to something approaching a real contest. An Angus Reid poll in June, 2010, found 82 per cent of British Columbians vowing to vote against the tax. A year later, that opposition had dropped to 56 per cent.

The challenge for the pro-HST campaign is motivating their often-tepid supporters to take the time to vote for a tax.

"The best shot for the HST to survive is to see a very high turnout," said pollster Kyle Braid, vice-president at Ipsos Reid. "A low turnout means only the most motivated voters took part in the process. I think it is reasonable to speculate those are the people who have been waiting to express their anger about the HST."

A very high turnout is subjective, but something north of 65-per-cent turnout would likely give the Smart Tax Alliance reason for optimism.

Last week, the province's chief electoral officer fuelled speculation that the turnout will be on the high side. The last mail-in referendum in B.C. brought out a mere 35 per cent of the vote, but Craig James said he's looking for turnout as least as high as the last general election -- 55 per cent of registered voters -- to validate the process.

As James is one of the few people who has been inside the secret warehouse stacked with boxes of returned ballots, the betting was that he was sounding bullish because he already knows a respectable share of the province's three million registered voters have taken the opportunity to be finance minister for a day.

Elections BC spokesman Don Main said Tuesday that regional collection centres across the province have already counted the ballots they received, and they're being recounted in Victoria. He said it wasn't clear when exactly Elections BC will have all the ballots and release the turnout figures,

Voters were asked whether the province should extinguish the HST. Those on the Yes side say a high turnout is no cause for despair.

"Who is more likely to vote? People who are opposed to the tax," says Fight HST strategist Bill Tieleman. "We're confident, whatever the turnout."

The government of Premier Christy Clark has been, to some degree, in a state of suspended animation while waiting for the outcome of the referendum. Once the referendum results are in, the next round of speculation will revolve around election timing.

An unexpected win on the HST would give Ms. Clark's troops a boost, but even a loss could offer a reason for a fall election.

"If they end up winning it'll be great for them, but if they don't, they can move on," said pollster Mario Canseco of Angus Reid Public Opinion. "It would be tougher for them to move on if they have been really fighting for it."

Clark did offer a "fix" for the HST in May, a package of changes that will come into effect only if the HST survives. But she hasn't personally vested herself in the campaign to save the HST.

With storm clouds gathering over the economy, Clark might see an opportunity to call an election in the fall on the grounds that she needs a mandate to manage the challenges of going back to the old system.

B.C. has a law that fixes the election day in the spring of 2013, but Clark, who won the Liberal leadership in February, has said she'd like to call an early election to obtain a fresh mandate for her government.

If the poll numbers for her party are encouraging, Clark might be willing to take a chance with voters this fall -- after all, the threat of tough economic times can work to the advantage of the B.C. Liberals. But those tea leaves haven't settled yet.