Melania Trump will run the gauntlet with anti-Trump protesters in London, while her husband and his bodyguards watch a special forces demonstration at a secret location in the English countryside.
The first lady will attend an event where she will meet ex-service personnel and school children in the capital. Thousands of demonstrators are expected to be protesting against the president.
The Independent reported last week how the UK government had helped organise a schedule that largely kept Mr Trump out of London, minimising any embarrassment if he were to be confronted by protests.
But it emerged yesterday that Ms Trump will, with Theresa May’s husband, stay in London for the event tomorrow while the president goes to see a joint exercise between British and US special forces.
A Downing Street spokeswoman said that around half past nine, the PM and the president would visit a defence site, but that the location could not be revealed for security purposes.
They will see UK and US special forces undertake a show of force, going through a “counter terrorism scenario and an outdoor capabilities demonstration, showing equipment special forces use when they conduct joint operations.”
The spokeswoman added: “The president and the PM will also have an opportunity to talk to special forces to meet US officer cadets who are studying at the defence site.”
“Since 2008, there has always been one US cadet in each intake, there are three intakes a year, ensuring that both British and American officers gain experience early in their army careers, in each other’s cultures and ways of working.”
The majority of Mr Trump’s schedule being outside London means it seems unlikely the president will come close enough to Westminster to see the “Trump baby blimp” protesters plan to fly over the house of parliament, after receiving permission from London mayor Sadiq Khan.
At the time Downing Street said the schedule was designed to make sure the president has a chance “to see and experience the UK beyond London and the southeast”.
But Ms Trump will partake in a different schedule on the Friday, with Mr May inside London.
The spokeswoman said: “On Friday she is going to have a separate programme in London and because it is in London I am not able to share the location.
“But she plans to meet veterans and local school children and she’ll be accompanied by Philip May.”
The president and first lady will fly on Friday evening to Scotland with details of their schedule north of the border yet to be confirmed, but it is understood that there will be limited government involvement in what was being described as a private element of the official visit.
Ms May is not believed to have any plans for travel to Scotland, where the president is expected to visit his luxury golf resort at Turnberry in Ayrshire.
Mr Trump is also thought to be planning a round of golf with an unnamed celebrity, possibly Prince Andrew according to some reports, and could also visit his smaller golf course at Menie Estate, north of Aberdeen.
Treasury secretary Liz Truss wrote to the Scottish government earlier this week to confirm that any policing costs associated with the visit on 13 July would be paid from London.
Ministers in Edinburgh were alarmed when the interim chief constable of Police Scotland, Iain Livingstone, estimated his force could need up to 5,000 officers, at a potential cost of £5m to properly police his visit.