Britain will pass a new law to change the rules of royal succession to the throne.
The proposed change means the first child of the Duke and Duchess of Cambridge - who announced they were expecting a baby on Monday (03.12.12) - will become third-in-line to the throne after Prince Charles and Prince William, regardless of whether it is a boy or a girl, and have the chance to become monarch one day.
The British government will introduce the Succession to the Crown Bill to be voted on in the House of Commons as soon as possible, after British Commonwealth members unanimously agreed the move would prevent discrimination against women.
Deputy Prime Minister Nick Clegg announced: "People across the realms of the Commonwealth will be celebrating the news that the Duke and Duchess of Cambridge are expecting their first child.
"We can also all celebrate that whether the baby is a boy or a girl, they will have an equal claim to the throne."
He added the legislation would build upon "what we agreed back in 2011 - that if the Duke and Duchess Cambridge have a baby girl, she can one day be our queen even if she later has younger brothers".
Male heirs currently take precedence over women in line to the throne, which was agreed in principle to be unfair in October 2011 at the Commonwealth heads of government meeting in Perth, Australia.
The new law will also lift the ban on anyone in the line of succession marrying a Roman Catholic.