LONDON — The British government will propose giving princesses the same rights to succeed to the throne as their brothers, announcing the plan a day after the news that Prince William and his wife, Kate, were expecting their first child.

Current laws, including the 1700 Act of Settlement, give male heirs precedence over their older sisters. The act also excludes Roman Catholics or anyone married to a Roman Catholic from becoming king or queen. Spurred on by William’s wedding last year, Prime Minister David Cameron agreed the law needed to be changed and lobbied his counterparts from other members of the British Commonwealth.