Anti-HST organizers in B.C. are encouraged by Premier Gordon Campbell's latest comments about a binding referendum -- now they want him to put it in writing.

Campbell has said his government will kill the harmonized sales tax if a simple majority of voters reject it in a referendum next year.

Currently, a successful Initiative referendum requires a majority of all registered voters in B.C., plus 50 per cent in at least two-thirds of the province's 89 ridings.

Fight HST leader Bill Vander Zalm says if Campbell is sincere, he must recall the legislature and rewrite the Initiative Act to set a lower bar.

Campbell has vowed to be bound by a 50 per cent referendum vote, regardless of the legislation, but fellow anti-HST campaigner Chris Delaney worries Campbell may not be in office at this time next year, and his successor might not honour the pledge.

Delaney also says a referendum must be held much earlier than the proposed September 2011 date, if the Liberals hope to avoid recall campaigns targeting the party's most vulnerable MLA's.