Research by a Westcountry lawyer has exposed the extent of the Queen and Duchy of Cornwall's power of veto over new legislation.
John Kirkhope has been battling with the Cabinet Office for more than two years for access to guidance from civil servants as part of his thesis at Plymouth University.
The papers, which show some 39 Bills approved by Parliament have required Royal consent or been vetoed, were only released after Mr Kirkhope's Freedom of Information Act request was backed by the courts after the Cabinet Office tried to block their release.
Mr Kirkhope, a notary public based in Weston-super-Mare, Somerset, stressed he was "not on a mission against the Queen or Prince Charles" but was involved in a "piece of academic research".
Mr Kirkhope added: "There has been an implication that these prerogative powers are quaint and sweet but actually there is real influence and real power, albeit unaccountable."
The internal documents, prepared by Cabinet Office lawyers, show ministers and civil servants are required to consult the Queen and Prince Charles in greater detail and over more areas of legislation than had been thought.
New laws which were sent to Buckingham Palace or the Duchy of Cornwall for consent include the Animal Welfare Act 2006, the Charities Act 2006 and the legislation which brought in fixed-term parliaments.
Andrew George, the Liberal Democrat MP for St Ives, has raised numerous questions about the power of the Queen and Prince Charles to veto Parliamentary bills.
"Most people believe that, over the centuries, the Royal family's role is primarily ceremonial," Mr George said.
"I am not engaged in a disrespectful republican plot but merely to ensure that democratically elected Members of Parliament are informed about the powers and influence of senior royals and also when and how this power is exercised."
The 30-page guidance outlines how the Queen's consent is likely to be needed for legislation affecting hereditary revenues, personal property or personal interests of the Crown or the Duchy of Lancaster, an estate covering some 47,000 acres.
Consent is also needed if it affects the Duchy of Cornwall which paid Prince Charles more than £18 million in 2012.
Mr Kirkhope was refused a copy of the 30-page internal guidance by the Cabinet Office. It was then ordered to do so by the Information Commissioner. The Cabinet Office later appealed to the Information Tribunal but lost.
A Buckingham Palace spokeswoman said: "It is a long established convention that the Queen is asked by Parliament to provide consent to those Bills which Parliament has decided would affect Crown interests.
"The sovereign has not refused to consent to any Bill affecting Crown interests unless advised to do so by ministers."
A spokesman for Prince Charles said: "In modern times, the Prince of Wales has never refused to consent to any Bill affecting Duchy of Cornwall interests, unless advised to do so by ministers."