British Prime Minister Gordon Brown said that he wants to scrap the 300-year-old law that forbids a Roman Catholic becoming monarch. Brown said that he would discus the issue with other heads of governments on the margins of a Commonwealth summit in Trinidad on Friday.

He also said he wanted to change the ancient rule of primogeniture, which puts men ahead of women in succession to the throne.

Allowing a Catholic monarch would mean changing the Act of Settlement of 1701. Brown told the House of Commons on Wednesday that he believes the Act of Settlement is out of date.

Changes of this magnitude, however, can only be made if all the realms that have the Queen as their head of state agree to them, Brown told the Commons. “That is why it is important to discuss this with all members of the Commonwealth including countries such as Australia and Canada,” he said.

Historically, Buckingham Palace has been opposed to any such changes. But today, many believe it is sympathetic to the idea.

Repealing the Act would have complicated legal ramifications, causing existing legislation to come under review and alteration, including the 1707 Act of Union. In addition, a Catholic on the throne of Britain would technically be the head of the Church of England.

British history contains centuries of power struggles between Britons and Catholic popes. England broke from the Vatican in 1534 under King Henry viii, establishing the British monarch as head of the Anglican Church. But now the pope is gathering the Anglicans back into the mother church. Talk of the obstacles to a Catholic monarch being abolished is another part of this trend. For more information, see our article “The Vatican’s Attack on Britain.”