New legislation ending discrimination against women in the line of succession to the British throne has been published.
The measure will mean that the Duke and Duchess of Cambridge's first baby can succeed to the throne, regardless of whether the child is a girl or a boy.
The Government has introduced the new law after receiving consent from all the Commonwealth realms to push ahead with the change.
The Succession to the Crown Bill will also end the ban on anyone in the line of succession marrying a Roman Catholic.
Deputy Prime Minister Nick Clegg said: "This Bill will bring to an end centuries of discrimination against women so that the first born is next in line to the throne, regardless of whether they're a boy or a girl.
"I'm delighted that all of the Queen's realms have agreed to this historic piece of legislation, that will enact in law what we agreed back in 2011 - that if the Duke and Duchess of Cambridge have a baby girl, she can one day be our Queen even if she has younger brothers.
"We're pressing ahead with this as quickly as we can - it's clearly something the entire country can get behind towards the close of this momentous Jubilee year."
The plan to end male primogeniture - the rule that discriminated against women - was announced at last year's Commonwealth heads of government meeting and was deemed to have taken effect immediately, even before the legislation was in place.
The legislation will be considered and voted on in the Commons as soon as parliamentary time allows, the Cabinet Office said.
