Voting has begun in the second national flag referendum, with papers being sent to residents throughout the country.

People are being asked to choose between the existing flag and an alternative design selected last year from five options.

The substitute flag features a silver fern in black, white and blue with a red Southern Cross.

It's a move away from the traditional Union Jack on the current design.

More than three million voting packs are being posted over the next week.

The referendum closes on the 24th of March and voters are asked to return their papers a few days earlier.