Trump has long voiced his support for Brexit, saying it was part of a global uprising that ultimately thrust him to power, and he was at his Scottish golf resort the day after Britons voted to leave the European Union, saying the outcome was a "great thing".
Activists inflate a giant balloon depicting US President Donald Trump as an orange baby in north London on July 10, 2018 ahead of a demonstration in London to coincide with the visit of the US president.
Firebrand politician and Trump ally Nigel Farage labelled the move "the biggest insult to a sitting US President ever" but others have welcomed the playful rebuke.
Before the visit, May lavished praise on the transatlantic relationship, while notably avoiding any direct mention of Trump himself.
Labour Party legislator Paul Flynn, who has criticized Trump in Parliament, says Trump has outraged Britons - and people around the world - with his harsh treatment of immigrants. But May and her ministers still hope to flatter Trump with pomp and royalty.
Other planned protests will occur near Blenheim Palace in Oxfordshire where Trump will attend a black-tie dinner and on Thursday outside the US's ambassador's residence in London where Trump and Melania will spend their evening.
U.S. President Donald Trump meets Prime Minister Theresa May this week, making a long-awaited first visit to Britain which will be closely watched to determine the health of the so-called "special relationship" between the two countries.
May has had to defend Trump's visit in the face of fiery criticism from opposition lawmakers.
He is also expected to visit Scotland - where he owns two golf courses - before heading back to the US.
Policing the visit will cost a minimum of £12m, with leave for thousands of officers cancelled, a particular strain for forces on alert for possible disorder amid England's World Cup campaign.
Almost every police force in England and Wales has contributed to cover the event - the biggest mobilisation since the 2011 riots - consisting of thousands of officers.
The state visit has never actually been scheduled - there is fierce opposition to it in many quarters of Britain - and this trip is part of a working visit instead, meaning among things that Trump will overnight at Winfield House, the USA ambassador's handsome residence near Regents Park rather than in Buckingham Palace or Windsor Castle as a guest of the queen.
"It is in the interests of the U.K.to stand up and take a firm moral stance", said Zoe Gardner, a researcher and spokesperson of the Stop Trump Coalition, which is organizing protests this week in cities across the country.
Trump "has proudly sparked passionate often divisive emotions about things, I think Americans living here to eager to turn out and express their views", he said.
"Turning somebody away and being deliberately antagonistic to them isn't the best way of trying to influence their decisions".