Image copyright AFP Image caption The proposed new flag, Silver Fern, was criticised as uninspiring by some

New Zealanders have voted to keep their existing flag after a national referendum, preliminary results show.

The referendum asked whether the flag which includes the Union Jack should be replaced by a design called Silver Fern, which won an earlier ballot.

The results show 56.6% voted for no change, while 43.1% opted for the new design. Just over 2.1m votes were cast.

PM John Key had advocated the new flag but called on New Zealanders to "embrace" the people's decision.

He was speaking after the preliminary result was announced following the close of the postal vote at 19:00 local time (06:00 GMT).

A final result taking into account late ballots will be announced next Wednesday.

Laser Kiwis and Silver Ferns: A tangled tale

The weirder designs that never made the cut

The 40-flag longlist the Silver Fern came from

The rejected fifth design that made it onto the shortlist in the end

Image copyright AP Image caption Mr Key has called on New Zealanders to embrace the decision

Mr Key said he was disappointed but would support the current flag.

Despite criticism of the cost of the vote and the process, he argued that it had at least generated discussion.

"You can't shy away from a debate or a discussion about nationhood," he told reporters.

The existing design features the British Union Jack, a legacy of New Zealand's days as a British colony and the reason many wanted to change it.

The proposed new design combines four red stars representing the Southern Cross constellation - also seen in the current flag - with a silver fern on a blue background with black infill in the corner - both motifs associated with New Zealand and its famous rugby team.

The Silver Fern was chosen in the first referendum last December from a shortlist of five candidates.

NZ flag exercise

Image copyright NZ Government

Process launched in 2014 by PM John Key, who favoured a flag change

A 12-person panel was set up to oversee the exercise and shortlist potential flags from thousands of entries submitted by the public

Four flags were chosen, with a fifth added after it gained support on social media

Postal voting took place over two referendums, one in end-2015 to decide a potential new flag, and the other in March 2016 to decide whether to change the flag

Final potential new flag was a black, white and blue design with a silver fern, by Kyle Lockwood

Total cost of exercise came up to NZ$26m ($17m, £12m)

One of the most vocal groups opposing the flag change was the military veteran group the Returned and Services Association. It called Thursday's result "an inspiring, strong show of democracy in action".

The lobby group Change the NZ Flag told the BBC that it would continue to push for a new flag.

"We'll keep campaigning, we have a strong support base and (there is still) strong sentiment, but simply the issues have got in the way of the process," its chair Lewis Holden said.

Media playback is unsupported on your device Media caption New Zealand long-listed 40 designs - but not any of these

Media playback is unsupported on your device Media caption What schoolchildren made of the new flag designs

The exercise has been mired in controversy from the start.

Many objected to the 12-member panel overseeing the process not including a designer, and the longlist whittled down from thousands of entries was said to lack imagination.

Many also described the process as unnecessarily expensive, with the bulk of the NZ$26m ($17m) cost going towards conducting postal voting.