A leaked Treasury document has called into question the accuracy of the Federal Opposition's cigarette tax costings.

Labor's policy document said its plan for gradual increases in the tax on cigarettes would raise $47.7 billion over 10 years.

But a Treasury document seen by the ABC said it would only generate $28.17 billion over the period.

The discrepancy could be significant because Labor has used the forecast savings to pay for other funding promises.

The ALP's policy document outlined a plan to increase the tobacco excise by 12.5 per cent a year, each year, from September 1, 2017 until September 1, 2020.

The plan would see a packet of 25 cigarettes cost more than $40 by 2020.

The Treasury document confirmed the Government will match Labor's policy.

Labor frontbencher Anthony Albanese told Sky the leaking of the document shows the Coalition was acting like an opposition.

"It says a lot about the character of Malcolm Turnbull and his team at the moment," he said.

In November, Labor's health spokeswoman Catherine King said the increase would bring Australia into line with the excise rates of about 33 other countries.

She acknowledged heavy smokers were some of the poorest people in society and promised more policies to help prevent and deal with smoking addiction.

"We want people to stop, we want more people to give up, we want more people who are in difficult circumstances to give up as well because we know that smoking kills people," she said.

"We'll be making some further announcements about what we might do to assist people, particularly those areas of the population who find it very difficult to give up smoking."