Three ferns and a black and white koru are the four designs that could go head-to-head with the current New Zealand flag in a referendum next year.

Photo: flag.govt.nz

The final four new national flag designs were revealed this morning.

The public will be asked to rank them to decide the final option in a referendum to be held later this year. This will determine which of the designs will run against the current flag in a second referendum in March 2016 to decide which flag New Zealand will use in the future.

The designs are:

Silver Fern (Black & White) designed by Alofi Kanter from Auckland

Silver Fern (Red, White and Blue) by Kyle Lockwood, originally from Wellington

Koru, by Andrew Fyfe from Wellington

Silver Fern (Black, White and Blue), also by Kyle Lockwood.

Photo: RNZ / Alexander Robertson

A panel chose 40 from more than 10,000 designs submitted by the public, and Cabinet signed off on the final four yesterday.

One of the long-listed designs - the 'Modern Hundertwasser' - had been removed following a copyright claim by the Hundertwasser Non-Profit Foundation, the panel said on its website.

Flag Consideration Panel chair Professor John Burrows said the panel's decision had been guided by its engagement programme, where thousands of New Zealanders shared what was special about the country, as well as the panel's own selection criteria.

He stressed the importance of designs being unmistakeably from New Zealand, timeless, free of any copyright or intellectual property issues and with the ability to work in a variety of contexts.

Read more on the Flag Consideration Panel's four alternative flag choices. (PDF 686 KB)

Prime Minister John Key said he favoured the two flag designs which featured the silver fern and the Southern Cross with two different colour combinations.

"I kind of like the fact that they have the fern ... I like the Southern Cross because I think it's got that connection with the old flag."

Mr Key said there were economic benefits for New Zealand in changing the country's flag.

"While I don't think about it in economic terms, I think ultimately if New Zealand had a new New Zealand flag, and that better reflected the nation, and we were more easily identified, there's huge economic benefits as well as other benefits for New Zealand."

The first referendum is set to be held between 20 November and 11 December, and the entire project is expected to cost over $25 million.