The B.C. Liberal government is about to face an unprecedented political fight against its plans to introduce a harmonized sales tax, say opponents, including former populist premier Bill Vander Zalm and the Opposition New Democrats.

Battleground HST will be fought on two fronts, inside and outside the legislature, say the NDP and Vander Zalm, past political foes now strangely united in their attack on the combined tax.

The two are tolerating each other. NDP Leader Carole James has appeared on the same anti-HST stage as Vander Zalm and each have complimented the other, but there are no signs of a co-ordinated barrage.

The New Democrats say they will use every procedural manoeuvre available to extend debate on the tax law, while Vander Zalm plans to take his campaign to the streets, community halls and recreation centres to sign up furious British Columbians who say they will vote to repeal the proposed law.

"We're going to keep beating the HST drum for as long as we can," said New Democrat House Leader Mike Farnworth.

"We will be lighting HST fires under the feet of any member of this government to get them to see the point that the people don't like it."

Farnworth almost dared the government to use the legislative hammer and force closure on the HST debate sometime this spring: "You are talking days and weeks and potentially months if we're able to use all that's available to us," he said.

The NDP wants seven Liberals to vote against their own government to defeat the HST law.

There are currently 49 Liberals, 35 New Democrats and one Independent in the legislature.

So far, no Liberals have indicated they will break ranks and vote against their own party.

B.C. Finance Minister Colin Hansen introduced legislation last week that ultimately joins the current seven per cent provincial sales tax with the five per cent federal Goods and Services Tax, creating a 12 per cent HST.

British Columbia is poised to join Ontario, Quebec, New Brunswick, Nova Scotia and Newfoundland and Labrador in introducing the HST.

Ontario voted in favour of the tax last December after the federal government offered the province $4.3 billion to buffer the blow of the HST transition.

Ottawa offered the B.C. government $1.6 billion to move to the HST, and the province has already used $750 million to offset its deficit budget.

Hansen said the value-added HST is the most important initiative the province can undertake to fight the recession.

The finance minister said the HST will save business an estimated $2 billion in costs, resulting in more investment, more jobs and lower prices.

But the New Democrats say the HST hits consumers by adding an extra seven per cent on many items -- such as bicycles, haircuts and funerals -- that were previously exempt from the provincial tax .

Vander Zalm, the former Social Credit premier during the 1980s who was known for his charming demeanour but resigned amid a political scandal, has launched a petition with Elections BC to repeal the law.

To succeed, he must collect the signatures of one-tenth of registered B.C. voters in every riding within 90 days, starting on Tuesday.

Vander Zalm, who has already been touring British Columbia gathering anti-HST support, will hold his first official rally on Tuesday at a high school in Premier Gordon Campbell's Vancouver-Point Grey riding.

"On the 6th of April, it's only appropriate and fair to the premier that we do it in his constituency," he said.

Vander Zalm said the HST punishes consumers and small businesses while tying British Columbia to the federal government, which gains more tax authority over the province.

"It's the dumbest thing politically that's ever happened in this province," he said.