Documents obtained by The Guardian under Freedom of Information legislation show how Balmoral and Sandringham were deliberately excluded from the Cultural Property (Armed Conflicts) Act 2017.

A private secretary for then Culture Secretary John Whittingdale wrote to Buckingham Palace to set out the government’s “wish to ensure that the powers of part 4 of the bill are not exercisable in relation to Her Majesty’s private estates”.

The Guardian said parts of the correspondence “appear to suggest the department used opaque language in a parliamentary bill that obscured the purpose of the exemption from the public”.

However, a spokesperson for the Department said: “It is incorrect to suggest that there was any direct attempt to obscure the purpose of any clause. It is common for legislation to include an exception for Her Majesty the Queen in her private capacity.”

A palace spokesperson added: “The royal household can be consulted on bills in order to ensure the technical accuracy and consistency of the application of the bill to the Crown, a complex legal principle governed by statute and common law. This process does not change the nature of any such bill.”