England, and the world for that matter, are pumped about the upcoming Royal Wedding of  William and Kate.

Planning the affair aside, it's now getting serious.   They're discussing succession to the throne.

The Associated Press says lawmakers say it would be the perfect wedding gift — changing Britain's rules of succession so any daughter born to Prince William and wife-to-be Kate Middleton would enjoy an equal right to the throne.

Lawmaker Keith Vaz led a brief House of Commons debate Tuesday calling for an overhaul of the 300-year-old procedures, which many call antiquated and sexist.

"Sex discrimination has been illegal in the UK since 1975 and those who break the law are rightly punished," he told Parliament. "This rule attempts to bring gender equality into our succession rules." He said a series of newspaper polls shows strong support for this change to the rules.

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The system currently gives sons an automatic preference over older female siblings to succeed to the British throne. That means if Middleton had a daughter and then a son, the daughter would be passed over and the son would become king when William dies or vacates the throne.

Vaz said Tuesday that William's April 29 wedding offers a once-in-a-generation chance to make the change, which has previously been discussed but never approved.

"Prince William looks like a very modern prince," Vaz said in a statement. "If he has a daughter first, it is only right that she become queen of England."

Any legal change would not effect Prince Charles — heir to the throne — or William, since neither of them have older sisters who would leapfrog them if new rules are adopted. And the issue would be moot for another generation if Middleton's first child is a boy.

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But rules specifying who inherits the throne, now based on the 1701 Act of Settlement, are not easy to change, particularly because it involves all 16 Commonwealth countries where Queen Elizabeth II is head of state.

Prime Minister David Cameron's office said that discussions have been taking place among the nations involved, but that it could be a lengthy process for any change to be approved.

"Amending the Act of Succession is a complex and difficult matter that requires careful and thoughtful consideration," a Cameron spokesman said on condition of anonymity in line with policy.

If an agreement wasn't struck, it could be possible that Commonwealth countries such as Australia or Canada might recognize a different king or queen than in Britain, said legal Prof. Noel Cox of Aberystwyth University in Wales. "That would be quite difficult," he said. "You're getting into fantasy here."

Though Vaz's effort to force the government into action is unlikely to result in any immediate legislation, he said it would provoke debate at a time of high interest in the royal family.

Rank and file lawmakers commonly use brief debates to generate publicity for their cherished causes, hoping to generate support among colleagues and the public.

By GREGORY KATZ, Associated Press