Prince William gifts Kate Diana’s 18-ct engagement ring.
Prince William and Catherine Middleton seen here as they announced their engagement. Press Association

A Labour Party MP is seeking to amend the laws of royal succession to the British throne to remove the supremacy of male heirs over females, ahead of the scheduled April wedding of Prince William and Kate Middleton.

Under the existing Act of Settlement of 1701, a younger male heir can supersede an older female in the line of succession to the throne.

Thus, if the first child born to William and Kate is a girl, she gave would not be first in line to become the monarch, if Kate later gives birth to a son.

Keith Vaz, Labour MP, seeks to change the existing law to remove any distinction between the sexes in determining the succession of the throne.

Vaz adds that laws governing the British Royal Family should be modernized.

The law was outdated in the 21st century, where people expect that discrimination of any kind should not exist and there should be equality regardless of race, gender or religion, he said.

Some of the United Kingdom's most successful monarchs have been women, no-one less than our present Queen, Elizabeth II. If the current succession laws did not exist, Princess Anne would be fourth in line to the throne rather than tenth, while her daughter, Zara, would be sixth in line rather than twelfth.

With the marriage of Prince William and Katherine Middleton , we have a once-in-a-generation opportunity to change the law. Prince William looks like a very modern prince. If he has a daughter first, it is only right that she becomes queen.”

However, it may be very difficult to alter the law.

It's not as straightforward a process as some who would wish it to move more quickly might think, said Constitutional Affairs Minister Mark Harper

Prime Minister David Cameron's office said that such reform would be complex and difficult and there seems to be little enthusiasm among the coalition government to make the amendment. For one thing, a change in the succession law would require the agreement and cooperation of 15 independent British Commonwealth countries which also call Queen Elizabeth their sovereign.

The Cameron government added however that it “accepts that the provisions in the Act of Settlement could be discriminatory.”

Currently, Prince William, 28, as the eldest son of Prince Charles, is second-in-line to the throne behind his father.