The New Zealand Government is coordinating a Commonwealth agreement to bring gender equality to royal succession rules, the British Deputy Prime Minister has told the House of Commons.

Commonwealth leaders at a summit in Perth last October supported a New Zealand push to allow an elder daughter to precede a younger son in the line of succession.

For centuries male siblings have leapfrogged older sisters to accede the throne.

The 16 nations who have the Queen as their head of state will each need to pass legislation to implement the change, however the news rules are effectively already in place on a "de facto" basis.


This means should William and Kate, the Duke and Duchess of Cambridge, have a daughter, she would accede to the throne ahead of any younger male siblings.

British Deputy Prime Minister Nick Clegg told the House of Commons New Zealand will be coordinating moves to obtain the consent of the Commonwealth countries to change the rules, the Press Association reported.

"I can confirm we will bring forward UK legislation to give effect to changes to the rules of succession once we have secured the consent of the other Commonwealth realms," Mr Clegg said.

"It's worth noting the change on gender will apply to a child born after the date of the Perth announcement, namely October 28 2011, even if the birth is before the legislation is actually passed."

A spokeswoman for the Prime Minister said the 16 countries which have the Queen as head of state agreed, in principle, in Perth last year to change the rules of succession.

"It was also agreed that New Zealand would coordinate processes across the 16 countries to ensure consistency in the timing and outcome of those changes. The New Zealand Cabinet Office, headed by the Secretary of the Cabinet and Clerk of the Executive Council, Rebecca Kitteridge, is leading the coordination effort.

"Ms Kitteridge is working with her counterparts in the other countries to discuss what actions they might consider taking to implement the proposed changes to the laws of succession."