Associate Health Minister Tariana Turia last year spoke supportively of tobacco tax increases in a speech that has put pressure on the Government on a range of tobacco policies.

She said that increasing the tax was "worth exploring if we are genuine about wanting to prevent uptake" of smoking.

As campaigners step up the pressure on ministers this year through a parliamentary select committee inquiry into smoking among Maori, the Herald has examined the likely outcomes in a three-part series starting on Monday.

The Government will not say whether tobacco taxes will rise this year or discuss the likely size of an increase. Health Minister Tony Ryall refused to be interviewed for the series and Mrs Turia's staff referred inquiries to the ministry.

However, acting deputy director-general Ashley Bloomfield said officials had advised Mrs Turia on a tobacco tax rise.

"No final decisions have been taken, but it's something that's definitely being considered. We do know there's good evidence that increasing the price ... does affect smoking rates. Young people are particularly sensitive to increases in price."

The excise tax on tobacco was last increased above the rate of inflation in 2000.

Smokers spend about $1.6 billion a year on tobacco, of which more than 1 billion is excise tax and GST.

Last year, the excise tax was around $6 for a $10 pack of 20 cigarettes, but because it is levied by tobacco content rather than per cigarette, roll-your-own smokes, which tend to be thinner, are in effect taxed more lightly than factory-made cigarettes.

Yet rollie smokers have been shown in research to suck out 28 per cent more smoke per cigarette, potentially putting them at even greater risk of smoking-related diseases.

The excise tax is increased annually in line with the consumers price index.

Smokefree campaigners have long pushed for a rise above the CPI and a double increase on loose tobacco, to bring thin rollies into line with factory-made cigarettes - and they appear to have Mrs Turia's support.

"Tax is one of our core strategies," said the Smokefree Coalition's director, Prudence Stone. "When the tax goes up, consumption goes down immediately. We need to have a schedule of tax increases up to 2020 that prices tobacco out of more and more wallets."

Smokers aged 18 or 19 are equally likely to smoke rollies or factory-mades. But those aged 15 to 17 are significantly more likely to smoke rollies than factory-mades, mainly because they are cheaper, ministry surveys show.

In the younger group, more than 40 per cent report being supplied by family members or friends, while 60 per cent said they bought tobacco themselves. The legal age to be sold tobacco is 18.

The coalition and its member groups are calling for radical policies to "denormalise" tobacco and accelerate the decline of smoking. They will urge the Maori Affairs select committee tobacco inquiry to agree.

Around 20 per cent of adults and 12 per cent of Year 10 students smoke regularly, but the rate of decline has slowed and the Maori and Pacific rates are still significantly higher.

A rising percentage of young people have never had a puff, which it is hoped will flow through into reduced adult smoking.