MPs are poised to vote on the alcohol purchase age next week.

Parliament's business committee met yesterday and is understood to have agreed to a vote on the age as early as next Tuesday.

MPs will have a conscience vote on whether to keep the purchase age at 18, move it back up to 20 or split the age to 18 for on-licence venues like bars and restaurants and 20 for off-licences like supermarkets and bottle stores.

The purchase age is one part of the Alcohol Reform Bill, which proposes a move to the split age. The other options will be put to MPs via amendments.

The rest of the bill includes new measures for more community control over the concentration, location, and hours of sale for alcohol outlets and new national maximum trading hours of 7am-11pm for off-licences and 8am-4am for on-licences and club licences. That part of the bill is expected to be debated next month, separately from the purchase age.

With a vote on the purchase age now seemingly a week away, last-minute lobbying is expected to lift a gear.

Youth wings of the main political parties have joined together to push for the age to stay at 18. National MP Nikki Kaye will move an amendment to the bill calling for the age to remain at 18. All of the Green Party MPs, with the possible exception of one, will support Ms Kaye's amendment, though it is unclear whether it will have enough support to pass.

The Law Commission, which carried out a major review of liquor laws in 2010, initially suggested a split age but shifted to back a return to 20 in its final recommendations. Another National MP, Tim MacIndoe, will move an amendment to push the age to 20, where it had been until it was dropped to 18 in 1999.

The age is the only part of the bill National MPs will be allowed a free vote on, whereas Labour MPs will be allowed to vote on conscience on the whole bill.

- © Fairfax NZ News