Late-night drinkers will be ejected en masse on to the streets of Wellington at 4am despite a last-minute plea to the Government by mayor Celia Wade-Brown.

It means through most of summer - including New Year's Eve and the Wellington Sevens - the city's bars will shut at 4am unless they apply for a special licence, with no guarantee it will be approved.

From December 18, a law change means the default position for opening hours for on-licences nationwide will be 8am to 4am.

But this week, Wellington City Council voted to finalise the city's alcohol management strategy, which allows maximum on-licence hours of 7am to 5am.

Ms Wade-Brown said it would take at least three months for the District Licensing Agency to approve Wellington council's rules, which could be applied for only after December 18.

This meant bars face two changes, December 18 and the eventual adoption of the capital's local plan, which would allow some bars to stay open till 5am. Ms Wade-Brown said during the limbo period the only way a bar could stay open beyond 4am was by applying for a special licence.

The mayor has written to Justice Minister Judith Collins to appeal for a transitional period, with the support of Local Government New Zealand, arguing the double law change could cause disorder in the streets.

But, in a reply obtained by The Dominion Post, Collins slapped the proposal down, saying "my decision is to not propose an urgent bill to Parliament to change the law supported by almost all of Parliament, to coincide with rugby events in Wellington in the next few months".

She said local government needed to show leadership in changing New Zealand's drinking culture.

Responding to The Dominion Post yesterday, Collins said 4am was a reasonable hour for people to go home.

"Nothing good is going to happen with people drinking in bars at 5am."

The council will now look at extra overnight trains or buses so people can get out of the city after 4am.