Britain said on Saturday it is looking into reforming ancient rules on royal succession to give any daughters born to Prince William and Kate Middleton the same right to the throne as their sons.
Under the 300-year-old law now in place, Prince William and fiancee Kate Middleton's first-born son would eventually become king, even if he had an older sister.
Male royal heirs have prior claim to the throne under the 1701 Act of Settlement, which also bans the monarch from marrying a Catholic.
With less than two weeks to go before the royal wedding, Deputy Prime Minister Nick Clegg took time out from political engagements to say the law needed to change.
"I think many people would feel that in this day and age if Kate and William were to have a daughter as their first child it would be reasonable to see whether we could change the traditions and conventions so that she could eventually ascend to the throne," Clegg, who is responsible for constitutional reform said. "But it's quite a complex issue, because it's not just up to the United Kingdom, that's of course something that affects other countries in the Commonwealth and elsewhere and that's why we are in discussions with them," he told reporters.
Buckingham Palace declined to comment on the plans, saying it was a matter for the government.
Britain's Queen Elizabeth II only came to the throne because she had no brothers.
If her son Prince Charles had died before having children, the succession would have passed to Prince Andrew, bypassing the Queen's second oldest child Princess Anne.
Clegg acknowledged change would not happen quickly, because It would require an act of parliament as well as legislation in the 15 other Commonwealth countries that have Queen Elizabeth as their head of state.
"It's not something that can be changed overnight it's a long historical convention, of course, which affects other countries as well."
The government's Cabinet Office said talks had begun with Commonwealth countries that would be directly affected by any change in the rules, but added that "it would not be appropriate to release details at this stage." (Reporting by Stefano Ambrogi; editing by Andrew Heavens)