Melbourne, Sept 25 : Even if Prince Williams' first-born child is a daughter, she would be the heir to the throne, if new amendments to England's constitution come into effect.
Earlier the successor to the throne had to be a male member of the Royal family.
Ending the 300-year-old exclusion of Catholics from the throne, Downing Street has drawn up plans to review the constitution.
Chris Bryant, the MP who was charged by Gordon Brown with reviewing the constitution, is drafting the plans, reports Guardian.co.uk.
The proposals also include limiting the powers of the Privy Council, in particular its role as arbiter in disputes between Scotland or Wales and the UK government.
For a long time, ministers have considered it anomalous that it is unlawful for a Catholic to be monarch but have not had the political will to risk reforming the law.
The 1688 Bill of Rights , the Act of Settlement in 1701 and Act of Union in 1707 - reinforced by the provisions of the Coronation Oath Act 1688 - effectively excluded Catholics or their spouses from the succession and provided for the Protestant succession.
According to these laws, neither Catholics nor those who marry them nor those born to them out of wedlock may be in the line of succession.
The law also requires the monarch on accession to make before parliament a declaration rejecting Catholicism.
While the Act of Settlement remains a cornerstone of the British constitution, critics have long argued about its relevance in the 21st century, claiming that it institutionalises religious discrimination and male primogeniture.
The Act of Settlement has barred dozens of people from taking their place in the order of succession.
Thus, any change in legislation would also require the consent of member nations of the Commonwealth.
Constitutional experts have argued that reform of the Act of Settlement and its related statutes would set in train an inevitable momentum towards disestablishment.
Also, disestablishing the Church of England would automatically remove the rationale for the religious provisions binding succession to the crown.