British American Tobacco (BAT) launched an advertising campaign in New Zealand Wednesday opposing plans to introduce plain packaging, in a move the government immediately dismissed as a waste of money.

New Zealand announced in-principle support for plain packaging in April and has enthusiastically welcomed world-first legislation in Australia forcing tobacco to be sold in drab, uniform packaging with graphic .

However, the proposal will not be formally adopted in New Zealand until the government finishes public consultations on the issue, prompting BAT to launch an advertising blitz aimed at winning support for its cause.

The campaign -- which includes print, radio and television advertisements, along with a website agreedisagree.co.nz -- has the slogan: "We agree that tobacco is harmful. We disagree that plain packaging will work."

BAT New Zealand general manager Steve Rush said plain packaging infringed on his company's intellectual property and set a dangerous precedent that could eventually spread to other products such as alcohol.

"The branding on our packs has been created over many years and it belongs to us... the government shouldn't be able to just take that away," he said, declining to reveal the budget for the campaign.

Rush said there was proof that plain packaging reduced smoking and it could backfire by fuelling an illegal market in and forcing down prices.

"It's unsound policy and potentially counterproductive," he added.

Rush refused to rule out legal action if the plan went ahead. However, adopted the same tactic in Australia and were defeated last week in a landmark ruling.

Tony Ryall did not believe BAT would sway .

"I don't know why they're wasting their money," he said.

"They can take whatever actions they want... but I think New Zealanders have moved on from being influenced in this way. There's a lot of support for what the government is doing with tobacco."

The public consultation on plain packaging ends in October, with a final decision expected a few months later.