The Queen is facing a million-pound black hole in her estates' finances after Brexit which has caused consternation among royal aides, The Sunday Telegraph has learned.
Sandringham Estate, the Queen's country retreat in Norfolk, will lose close to £700,000 a year when EU farming subsidies end while the farms near Windsor Castle will be around £300,000 down.
Prince Charles's estates are also facing a funding cut from Brexit of £100,000 a year while the Crown Estate - which manages Royal land - will also be hit.
A source familiar with Buckingham Palace's finances said there had been concerns since before the EU referendum about the impact of losing the grants.
While people were not "throwing their hands in the air in despair" there was anxiety about how the current level of EU farming grants will be sustained, the source said.
They added that the Keeper of the Privy Purse, who looks after the Queen's finances, would likely be sounding out Government figures - though no meetings are known to have taken place.
Ministers are now under pressure to break their refusal to provide commitments for post-Brexit Britain and publicly say the payments will be continued.
Estates and country houses across Britain as well as farmers benefit from Common Agricultural Policy [CAP] payments - the EU's system of rural support.
The billions of pounds of subsidies will end when Britain leaves the EU, which on current timescales will be in spring 2019.
Ministers have sought to reassure the farming community by guaranteeing payments until 2020, but have refused to make commitments beyond that.
Analysis by The Sunday Telegraph has revealed the full extent to which royal estates benefit from the subsidies, totalling more than £1 million last year.
In 2015, Sandringham received £665,000, the Royal Farms in Windsor got £298,000, the Duchy of Cornwall was given £129,000 and the Crown Estate got £350,000.
A source familiar with the Royal finances warned the loss of funding had caused concern before and after the EU referendum.
"I don't think it was a budget-busting concern, it wasn't something people were losing sleep over. But it was something people were conscious of as a post-referendum impact," the source said.
"I think that they were interested to see what the Government's view was on what the replacement mechanism would be for the CAP domestically."
The source added: "The question is are you losing £700,000 or is there a successor mechanism in place domestically that offsets the Brussels package?"
It comes amid wider fears about how the Crown Estate, which looks after Royal land, is being impacted by Brexit.
It is understood there were concerns about whether demand for stores on Regent's Street and other parts of London owned by the Crown would drop after a vote for Brexit.
All revenue made by the Crown Estate goes to the Treasury, with 15 per cent of the taking shared to the Royal Family through a yearly Sovereign Wealth Fund.
However a Crown Estate source said last night: "Businesses are still queuing round the block to take retail space on Regent's Street and St James's."
Sir Gerald, a Tory former defence minister who backed Brexit, said: "What we all said during the Leave campaign was that all those currently in receipt of so-called EU money will continue to receive the same money because we will be saving £20bn every year."
"We must reassure the recipients - whether it's Her Majesty or farmers - that they will continue to benefit from the current arrangements."
"What Brexit does is to give the United Kingdom the chance to fashion a farm price support mechanism designed exclusively for the benefit of British farmers."
Dickie Arbiter, a former Buckingham Palace press secretary, said: "After Brexit Her Majesty would fall in line with everyone else currently entitled to CAP and would not wish to be considered a special case or come in for special treatment."
A Buckingham Palace spokesman said: "Subsidies are open to all farmers; and like others with agricultural interests, subsidies are received on The Queen's private estates.
"We would not comment beyond the detail that is already in the public domain as a matter of record."