Ministers and courtiers fear President Trump could embarrass the Queen by publicly backing Brexit in front of her at a Buckingham Palace banquet tomorrow.

Officials involved in the planning of the controversial State visit are braced for Mr Trump to use his banquet address to heap praise on the UK's decision to quit the EU, despite the Royal Family's scrupulous attempts to remain above the political fray.

Palace sources last night insisted the Queen would be 'more than capable' of dealing with such controversy and Foreign Office insiders said they had not broached the subject with Washington.

A Whitehall source said: 'We've learnt that asking them to steer the President off a subject tends to have the opposite effect.'

Aides fear that President Trump will breach protocol by endorsing Brexit in front of the Queen (pictured with the Queen in 2018)

And a Palace insider added: 'We are not in the business of telling a foreign leader what they can and cannot say for political reasons.'

However, such an intervention by Mr Trump would cause fury, given the lengths to which the Palace has gone to distance the Queen from the divisive debate about Britain's relationship with the EU.

When one newspaper accused the Queen of supporting Brexit in 2016, the Palace made a furious and unprecedented complaint to the Press regulator.

Comments about Brexit would mark a second breach of protocol by the President following his unusual endorsement of Boris Johnson to be the next Prime Minister – before Theresa May has officially resigned.

The president is a supporter of Brexiteers like Nigel Farage - posing together by the golden elevator in his New York penthouse

And after his diplomatic gaffe of backing the current Tory leadership frontrunner, Mr Trump is poised to anger Downing Street further by meeting Brexit Party boss Nigel Farage.

Mr Trump last week described him as a 'friend' and it is thought the pair could be guests at a dinner hosted by the President on Tuesday evening at the official London residence of the US Ambassador. Spokesmen for both men said last night they had yet to receive such an invitation.

In a separate development, Foreign Secretary Jeremy Hunt was forced to deny that he had pleaded with Mr Trump to endorse his bid for No 10, after the President said in an interview that some of Mr Johnson's leadership rivals had sought his blessing.

A Foreign Office source said that while it was true that Mr Hunt was in regular contact with Mr Trump's son-in-law and adviser Jared Kushner, it was 'categorically untrue' that he had sought an endorsement.

Palace sources insist that the Queen will be able to cope with anything that Mr Trump might say. The president is a noted fan of Brexit Party leader Nigel Farage

Foreign Office insiders said they had not broached the subject of the president's speech with Washington

Jeremy Corbyn condemned Mr Trump's intervention in the leadership contest. 'President Trump's attempt to decide who will be Britain's next Prime Minister is an entirely unacceptable interference in our country's democracy,' said the Labour leader, who has snubbed an invite to tomorrow's State banquet.

Mr Trump responded to the Labour leader's decision by saying Mr Corbyn was 'making a mistake' in not attending because as a potential future Prime Minister 'he would want to get along with the United States'.

Commons Speaker John Bercow is also boycotting the banquet.

The Government last night pleaded with the public to welcome Mr Trump to London, arguing that 'the special relationship is generational, not one person'.

Home Office Minister Ben Wallace said: 'The relationships are daily and long-developed relationships. You don't unpick that. The special relationship is not Presidents and Prime Ministers.'

The US president also praised hard Brexiteer Boris Johnson, and it looks as if he will meet with the Foreign Secretary during his visit

Arriving on June 3, President Trump will be welcomed by the Queen at Buckingham Palace (left). The president will also have tea with the the Prince of Wales and the Duchess of Cornwall (right) at Clarence House

Last night, President Trump's intervention sparked calls for the Queen to scrap tomorrow's banquet, to punish him.

Liberal Democrat MP Sir Ed Davey, a former Cabinet Minister now bidding to replace Sir Vince Cable as his party's leader, said: 'The Queen would be perfectly entitled to cancel Trump's dinner, given he's insulted the Duchess of Sussex and interfered in the selection of our next Prime Minister at a time of national crisis.

'We don't need friends like that.'

Sir Ed was referring to interview comments Mr Trump made describing the American-born Duchess of Sussex as 'nasty' over comments she made in 2016 threatening to move to Canada if he became President.

Six glasses each, four menus and 12 pipers

President Trump and his family will be wined and dined by the Queen and other Royals tomorrow night, along with 170 guests picked for their cultural, diplomatic or economic links to the US, in the opulent Buckingham Palace Ballroom (pictured right).

Former Buckingham Palace chef Darren McGrady described such events as 'military operations', with menus planned months in advance. All food will be the 'best of British' but there is likely to be a nod to Trump's Scottish heritage – with perhaps traditional shortbread or salmon.

The exquisite menu served on priceless silver-gilt dinner plates and cutlery from the Grand Service made for George IV, take three days to lay at the vast U-shaped table, each place setting exactly 18in from the next, checked for precision with special measuring sticks.

Staff members lay the State Banquet table, in the ballroom at Buckingham Palace, London, ahead of the summer opening of the royal house to the public

The exquisite menu is served on priceless silver-gilt dinner plates and cutlery from the Grand Service made for George IV

Chefs will have been given some rough guidelines, and then prepared four menus. These will have been given to the Queen, who decides which she wants.

Each guest has six glasses – for water, red and white wines, a champagne toast, a dessert wine and port, all embossed with the Royal crest.

Nineteen serving stations are set up around the walls of the room, each manned by four staff – each station linked to a traffic light system to co-ordinate the serving of courses.

The footmen must make sure every chair is exactly the same distance from the table and each glass is the same distance from the front edge of the table.

Detailed diagrams are used to illustrate the serving plans and a list of special instructions sets out any dietary requirements and requests for the Royals and other guests.

Each guest has six glasses – for water, red and white wines, a champagne toast, a dessert wine and port, all embossed with the Royal crest

President Trump will be accompanied by First Lady Melania and four of his five children – Donald Jnr, Eric, Ivanka and Tiffany.

Just before the banquet, members of the Royal family will be lined up in the White Drawing Room to be introduced and shake hands with Mr Trump and the First Lady. The Queen and the President will then make their way into the Ballroom side-by-side.

Two silver gilt three-branch candelabra, each cast as a fruiting vine stem, will adorn the table.

The Queen will be seated next to Mr Trump at the top end of the table, along with his wife, Charles and the Duchess of Cornwall. Other Royals will be spread between the guests.

Two silver gilt three-branch candelabra, each cast as a fruiting vine stem, will adorn the table

Four large silver gilt scallop shell soup tureens, each surmounted by a triton blowing a conch shell horn

Speeches start at 8pm when the Queen and Mr Trump will both formally address the gathering and propose toasts to one another, followed by the playing of the national anthems.

A string orchestra usually provides the musical backdrop and the end of the banquet is signalled by the arrival of 12 pipers in a procession around the room, a tradition begun by Queen Victoria.

The dress code is white tie and tiaras. Members of the Royal family wear sashes and badges known as orders if they have been given them in recognition of Royal service.

Four large silver gilt scallop shell soup tureens, each surmounted by a triton blowing a conch shell horn, are some of the most striking pieces in the Grand Service.