Wellington, Feb 1 NZPA - Cabinet hasn't discussed raising tobacco excise and no decisions have been made, Prime Minister John Key says.

The Maori Party, one of the Government's support parties, is lobbying hard for an increase because it believes increasing the price of cigarettes would be a strong deterrent to smoking.

Maori Party co-leader Tariana Turia, an associate health minister, is due to present a paper to Cabinet outlining the case for an increase.

"Whether that ultimately happens or not is not something the Cabinet has considered at this point," Mr Key said at his post-cabinet press conference today.

"There's been strong arguments put up by Tariana Turia, we accept that she feels strongly about the issue, but we haven't made the decision yet."

Mr Key said if tobacco excise was increased, it was possible it would be included in the May budget.

"Or it could happen at some other time. We haven't actually had the debate about whether it would happen and, if it happened, when it would happen."

Mr Key said he knew evidence showed that the most effective way to stop people smoking was to increase the price of cigarettes.

"We have to think through all those issues. We haven't done that yet and I don't want to prejudge Cabinet discussions."