A lengthy debate, one of the most detailed to date, is set to begin in Parliament today on the Alcohol Reform Bill.

The bill overhauling New Zealand's liquor laws is back from its committee stage, and will be debated at length after a forced conscience vote on more than 20 amendments to the bill.

Delay tactics could result in 22 hours of voting.

Justice Minister Judith Collins said the Labour Party is responsible for creating a delay after deciding to vote on each amendment on conscience, rather than as a party bloc.


National MPs will vote as a bloc for the bill and against all amendments put forward by opposition parties.

"If they want to speed things up the best way they can do it is drop the conscience vote they're having for every single thing - this is simply going to delay the process.

"They should stop the silly nonsense about voting and get on with it," said Ms Collins.

MPs have already voted to keep the alcohol purchase age at 18.

Today MPs will vote on the 270-page bill and introduce their own amendments.

Amendments include one put forward by Labour to ban liquor sales from off-licences after 8pm, and a minimum pricing regime.

Labour MP Phil Twyford is pushing for a late change, calling for councils to be able to exercise their powers a lot faster.

He said it would take at least 16 months under current legislation before councils can put their new local alcohol policies in place.

The policies allow councils to control the number and location of liquor outlets and their opening hours.

Mr Twyford is pushing for councils to be able to put the policies in place within seven months.

Ms Collins said it was reasonable for councils to wait 16 months after the bill becomes law before they can implement new local alcohol policies under the bill.

She said there was a lot of consultation to take place before the policies became law at council level, and councils won't be ready in time if the timeframe is reduced to seven months.

"It's really important that they get them right. They actually want to have that time to get themselves in place," she said.

"There hasn't ... been a definitive statement about what's actually in the final bill. Councils can't prepare like that. They can't prepare on what might or might not be there."

Green MP Kevin Hague is calling for an excise tax increase across-the-board of 50 per cent on all liquor.