Critics of the Harmonized Sales Tax say there's no reason to hold the referendum on scrapping the tax until next fall when it could be over and done with this year.

NDP Leader Carole James said the decision to wait until September 2011 will cause a year of economic uncertainty and allow the government to spend money on a costly HST advertising campaign.

"How many taxpayer dollars are they going to use to try and convince people that the HST is good for them?" she asked. "There's no reason why (Premier Gordon Campbell) couldn't move the date up and hold the referendum sooner."

Campbell told CTV News Channel he believes if the public hears about the benefits of the tax they will be on board by next fall.

"I have confidence that British Columbians will say, actually, they don't really like the way we (introduced the HST) but it does make sense as we go forward in the 21st century."

Representatives from the forestry, mining, energy, agriculture, transportation and construction industries will come out in defence of the tax over the next year, Campbell predicted.

The premier also pledged to disregard official referendum rules and repeal the tax if a simple majority votes it down.

An all-party legislative committee had previously decided on a $30-million, non-binding referendum that would have required the difficult threshold of 50 per cent of registered B.C. voters to pass.

Former B.C. premier Bill Vander Zalm, a leader in the anti-HST crusade, argued that Campbell's pledge will be meaningless if he's no longer in power by next fall -- and his potential replacement might not honour the referendum results.

Vander Zalm wants the legislature to amend the Initiative Act to match Campbell's pledge. If it doesn't, he threatened that vulnerable MLAs could face recall campaigns.

"We want it done democratically, properly, through the legislature. If that's done then we'll not be getting into recall," he said. "It was never our intent to overthrow a government but we'll go into recall if that's what it takes."

James also said she worried the referendum would be awkwardly or confusingly phrased to mislead voters, a concern Campbell dismissed.

"This will be a straightforward question; there will be no ambiguity about it," he said. "We're there to serve the public."

With a report from CTV British Columbia's Mike Killeen