Labour's leader says New Zealand needs to become a republic before it changes its flag.

Kyle Lockwood's black and blue silver fern flag is ahead in provisional results for the first flag referendum.

If it wins, it will go up against our current flag in the second referendum next year.

Andrew Little thinks New Zealanders will probably vote for the current flag, because now's not the time to change.

"If and when we get around to changing our constitutional arrangement and we become truly independent and have our own head of state then that's the time we should look at changing the flag."