The Help End Marijuana Prohibition lobby yesterday announced it had changed its candidate for the Mundingburra by-election.

Billy Tait, a 27-year-old Botany student at James Cook University, replaces Steve Dimitriou who had announced his candidacy on the weekend.

But like Mr Dimitriou, Mr Tait said HEMP would direct preferences to Liberal candidate Frank Tanti unless Premier Wayne Goss considered dropping his opposition to the decriminilisation of cannabis.

"We are open to negotiations on preferences with the state government if it reconsiders its stand, " Mr Tait said.

Mr Tait said he was a qualified fitter and turner who was studying botany because he was interested in the industrial production of hemp. He said he had never stood for parliament before.

Mr Dimitriou said he would direct Mr Tait's campaign.

He said he had decided to pull out so that HEMP could be represented by someone who lived in the Townsville area. He said HEMP's change of candidate had been negotiated amicably -- unlike in the ALP.