Eleven legal objections to the wedding of Prince Charles and Camilla Parker Bowles have been dismissed by Registrar General Len Cook.
Critics have said the legal basis is unsound
A marriage certificate will now be granted for the ceremony at the Guildhall in Windsor on 8 April.
Critics have said it is illegal for the prince to marry in a register office, although the government believes it is legal because of the Human Rights Act.
The objectors can now petition for a judicial review of the decision.
In a statement on Tuesday, Mr Cook said the objections - or "caveats" - had stated that members of the Royal Family were a special category with special rules.
He said those who had lodged caveats had said the Marriage Act 1949 states that "nothing in this act shall affect any law or custom relating to the marriage of members of the Royal Family".
This led them to argue that the provisions of the 1949 act governing civil marriages do not apply to marriages of members of the Royal Family.
He said a reading of the 1949 act which stopped the prince and Mrs Parker Bowles from marrying would breach their civil liberties under the Human Rights Act and the European Convention on Human Rights.
The "natural" reading of the 1949 act was that it preserved certain regulations and customs relating to Royal marriages, but that it did not exclude members from marrying in civil ceremonies as outlined by the act.
Mr Cook said some other objections were considered and dismissed.
The objections were received by the superintendent registrars at Chippenham and Cirencester, local offices for the Prince of Wales and Mrs Parker Bowles.