Wellingon, Sep 1 (IANS): A government-appointed panel on Tuesday unveiled its final shortlist of four alternative designs for New Zealand's new national flag.

The Flag Consideration Panel unveiled the final four designs -- three show variations on the silver fern design. The fourth option is a koru, or unfurling fern frond, in black and white.

Speaking in Auckland, Prime Minister John Key said it was no secret he was a fan of the silver fern design.

The fern was internationally recognisable and Kiwi athletes, including New Zealand national rugby team, All Blacks captain Richie McCaw, had already spoken up in favour of a design that incorporated the silver fern, he said.

The fern had a rich history and was on the headstones of New Zealanders who died in service of the country and were buried overseas up until 1978.

Key said he believed the designs had elements of New Zealand's past as well as representing its current multi-culturalism.

"I reckon there's a really strong argument to do that because it is ultimately about the future of the country and the way we show the world the pride and passion that we know New Zealanders have."

The New Zealand public will now rank these four designs in order of preference in a binding postal referendum to be held between November 20 and December 11. A second referendum, to be held in March 2016, will pit the preferred alternative against the current flag.

The final options were chosen from more than 10,000 designs that were submitted when the process was opened up to the public earlier this year.