[3] King's or Prince's Consent must be obtained early in the legislative process, generally before parliament may debate or vote on a bill.
According to the 1851 edition of Erskine May, the manual of UK parliamentary practice, the practical advantage of Queen's Consent (as it then was, Queen Victoria being on the throne) was that it enabled the Crown to protect its rights without having to resort to blocking a bill after its passage by refusing royal assent.
More recently, however, there has been criticism of the Crown being consulted on the content of forthcoming bills, and being given "the right and opportunity to shape prospective legislation".
[5] Critics allege that even though the Crown may never formally withhold its consent contrary to government advice, the procedure is nevertheless being used to vet and change draft bills before they reach Parliament.
[8] There is evidence of consent first being invoked in 1728 when George II gave Parliament permission to debate the Suppression of Piracy bill, which suggests that it has been part of the UK legislative process for several hundred years.
[10] Recent editions of Erskine May drop discussion of the advantages of the practice, and simply state that under certain conditions consent is "required",[11] leaving unsaid the implications of its not being given.
If a bill is mistakenly allowed to progress even though the required consent was not signified and the error is discovered before royal assent has been given, the proceedings may later be declared void.
In 1999, the Queen, acting on ministerial advice, refused to signify her consent to Parliament debating the Military Action Against Iraq (Parliamentary Approval) Bill.
This was a private member's bill which sought to transfer from government (strictly speaking, the monarch acting on ministerial advice) to Parliament the power to authorize military strikes against Iraq.
[30] While the website of the royal family describes consent as "a long established convention", The Guardian newspaper reported in February 2021 that memos had been found in the National Archives revealing that the advance notice of forthcoming bills allows the monarch to lobby for legislative changes without actual consent being invoked.
The documents were reviewed by Thomas Adams, a specialist in constitutional law at Oxford University, who said they revealed "the kind of influence over legislation that lobbyists would only dream of", adding that the existence of the consent procedure appeared to have given the monarch "substantial influence" over draft laws that could affect her.
In 1973, when a companies bill incorporating transparency measures was to be introduced in the UK Parliament, after receiving advance notice as required by the consent procedure, the Queen's lawyer and the trade department agreed an exception for heads of state.
Documents revealed that Charles wrote to the Prime Minister John Major expressing his "particular concern" about this aspect.
The government did not wish to grant this exception, fearing that it would create a precedent for other major landowners, but ultimately, reluctantly, included the special exemption to avoid what a Whitehall official described as "a major row with the Prince of Wales", saying "the will of ministers can prevail over that of monarchy but a constitutional crisis would add a further dimension of controversy to the bill which would be better avoided".
[35] It was reported in July 2021 that the advance notice provided by the consent procedure was used in the Scottish Parliament in 2021 to arrange for draft legislation to be modified so that the Queen, one of the largest landowners in Scotland, would become the only person in the country not required to facilitate the construction of pipelines to heat buildings using renewable energy.