The Government is not bound by any principles in the Treaty of Waitangi to include Maori symbols on a new flag, Prime Minister John Key says.
Mr Key on Tuesday announced National would hold a referendum on the flag in the next parliamentary term - if it's re-elected on 20 September.
The design of the current flag symbolises a colonial and post-colonial era whose time has passed, he said. But whether or not a new ensign would include Maori symbols, including native flora and fauna, would be up to the public to decide.
Mr Key said the Government had no obligations under the Treaty to include any Maori designs - the same situation as there was in 1902, when the current flag was chosen.
He was open-minded about the options for a new flag, he said, adding that a lot of Maori culture is treasured and loved by a wide range of New Zealanders - not just by Maori.
Mr Key said if he was still prime minister after the election he would ask all political party leaders represented in Parliament to nominate an MP to join a cross-party group on flags.