Republicans have reacted with horror to the revelation that the Queen and the Prince of Wales exercise their power to veto legislation that is proposed by parliament, with the monarch even having blocked an attempt to hand MPs the power to declare war.
On Tuesday, the Guardian revealed that at least 39 bills had been subject to the monarchy's power to agree to or block new laws.
The information came to light after Downing Street lost a court battle with the paper to prevent publication of the internal Whitehall record.
Graham Smith, the chief executive of Republic, the campaign group which wants to get rid of an unelected head of state, said the royal veto was "a serious affront to our democracy".
"It is extraordinary that in this day and age our elected politicians have to ask the permission of the Queen and her eldest son before they can pass new laws," he said.
"With Prince Charles routinely interfering in politics we can now see that he has real leverage over ministers. It's no wonder they pay such close attention to his views."
"The palace's claims this is nothing more than a formality are unbelievable: why did the government fight tooth and nail to keep this information secret? It is time we had full disclosure on the extent of this royal power and how it has affected the laws we now all live under."
The Cabinet Office document shows that among the new laws that required the Queen's consent was the Civil Partnership Act 2004 as it contained a clause about the validity of the relationships "that would bind Her Majesty".
And the government was obliged to ask the Prince of Wales for his consent for the Merchant Shipping and Maritime Security Act 1997 as he owns the harbour of the Isles of Scilly through the Duchy of Cornwall.
The Queen also vetoed entirely a private member's Bill, the Military Actions Against Iraq (Parliamentary Approval) Bill 1999, that would have transfered the power to authorise military strikes against Iraq from the monarch to Parliament
It is widely assumed that the royal prerogative, the authority to declare war, rests now with the prime minister rather than the Queen herself.
However, these documents raise questions about how much power the monarch still has over the elected government of the day.
Lib Dem MP Julian Huppert said the fact there had been a "fight to to keep this quiet" showed the significance of the Whitehall document.
"It's quite concerning there is wider influence, and secretive influence, of the monarchy in these things than had previously been revealed," he told The Huffington Post UK.
And he said he was particularly concerned about the revelation the Queen had fought to keep parliament from gaining the power to authorise, or block, military action.
"The power to go to war is an incredibly important thing," he said. "It's important to bring the country on side and to do things in a clear way and leave the choice up to parliament.
He added: "I think it's astonishing that the first vote on Afghanistan happened in this parliament, there wasn't one before that, that's absolutely astounding in what claims to be parliamentary democracy."
And Labour MP Paul Flynn told HuffPost that the revelations showed Britain was a "long way from having a full democracy".
And he said the Monarchy had "so many privileges" the idea they could "amend or frustrate legislation" was "not part of the deal".
Lib Dem Andrew George told The Guardian:"This is opening the eyes of those who believe the Queen only has a ceremonial role."
"At any stage this issue could come up and surprise us and we could find parliament is less powerful than we thought it was."
On Tuesday Cabinet Office minister Chloe Smith said the "signification" of the Queen's and the Prince of Wales's consent for certain Bills was "a parliamentary requirement" and noted that neither had refused to consent to any government Bill in the last 10 years.
In a parliamentary answer given to George, she said the government did not hold figures for how many bills have required royal consent over the last 10 years and to collect such data would "incur disproportionate cost as there are many bills in each session".
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."