Less than a day after internal documents revealed that the BC Liberal government was talking about introducing the HST five months before the 2009 election, there are calls for the resignation of Premier Gordon Campbell and Finance Minister Colin Hansen.

Briefing notes, emails and internal correspondence from B.C.'s Ministry of Finance released to media Wednesday showed that BC Liberal bureaucrats were conducting cost-benefit analyses and preparing lengthy briefing notes on the tax for Minister Colin Hansen.

The documents directly contradict statements by both Campbell and Hansen, who repeatedly said the tax "wasn't anywhere on the radar" before the election.

Former B.C. premier Bill Vander Zalm is calling the incident "the biggest lie in the history of the province."

"This document shows the premier and finance minister not only did not tell the truth during the election, but they repeated that deception over and over again afterward. Now they've been caught red-handed, and they must resign," he told CTV News.

Vander Zalm's sentiments were echoed Thursday when the president of a BC Liberal cabinet minister's riding association temporarily called for Colin Hansen's resignation, saying the documents have caused his reputation to be "completely shot."

"Under his ministry, the handling and implementation of the HST has been one blunder after another," Jordan Bateman, who is the president of Housing and Social Development Minister Rich Coleman's Fort Langley-Aldergrove riding association, said in a blog entry.

"The problem for me isn't even that the information went to Colin Hansen, in a memo before the election. It's that Hansen has repeatedly claimed it wasn't on the radar. It was on his desk, but not his radar?"

But Bateman quickly retracted his comments and issued an apology to Hansen, after speaking with the finance minister, whom he described as "gracious" during the telephone conversation.

"I want to apologize to the Minister for my earlier comments (in fact, I apologized to him directly on our phone call). They were spoken out of frustration after reading the volumes of media coverage over the past 24 hours," Bateman wrote.

"We spoke about the documents and I feel you should all know that Minister Hansen gave me his direct assurance that the HST was not being planned prior to the election."

Colin Hansen told CTV News that even though his top bureaucrats were discussing the HST and preparing documents and cost-benefit analyses as early as January 2009, he was not made aware of it.

"At no time did this government ask finance officials to proactively do this work," Hansen said.

"This info gathering, up until the end of May was at their initiative and was not something we asked them to undertake."

One of the documents is an 11-page briefing note given directly to Hansen which outlines the pros and cons of harmonizing the tax. The cover page reads: "There is a strong possibility that the British Columbia government will be asked in the next couple of weeks about its position of harmonization."

Vander Zalm says the "damning" documents, which includes a C.D. Howe report that suggests the tax would have a negative impact on the economy for at least five years, amounts to a great deception on the part of the provincial government.

"The [government] also told us the HST was the best thing they could do for the economy of B.C. It turns out they were not telling the truth about that either, since they were fully aware of a C.D. Howe Institute study showing the exact opposite," he said.

"This is the biggest lie in the history of the province. It's terrible."

Opposition New Democrat Leader Carole James said Wednesday she didn't understand why the Liberals would bring in a tax when it had information that it could damage an already struggling economy for another decade.

James calls the documents "just another betrayal of trust to the public" by the BC Liberals.

"From the start the premier, the finance minster, BC Liberal MLAs have been saying over and over to the public that the HST wasn't on their radar screen before the election. It's very clear from these documents that it was," James said.

"They were looking at options, they were exploring the HST."

Vander Zalm says the revelations will cause British Columbians to question their government leaders. He recommends that the premier calls the B.C. legislature back into session immediately and cancel the controversial tax.

"It's their only hope. Cancel the HST, admit they haven't been truthful with the people and then suffer the consequences."