Max Wakefield, one of those behind the balloon, inflated it again last week in a London park in preparation for the visit.

He told the Reuters news agency: "He is the most powerful bully in the world. His power is built on division and about trashing the rights of some of the most vulnerable communities."

Protests and security concerns prevented Trump from making a full state visit before, despite him having been invited to do so two and a half years ago. On one occasion, a visit was postponed when the British people reacted angrily to Trump's criticism of London's mayor, Sadiq Khan, in the wake of a terror attack in the UK capital.

Khan said on the weekend that the language Trump uses on his supporters is similar to the rhetoric of "the fascists of the 20th century", telling the Observer newspaper he is "one of the most egregious examples of a growing global threat".

"The far right is on the rise around the world, threatening our hard-won rights and freedoms and the values that have defined our liberal, democratic societies for more than 70 years," he added.

Many other UK politicians are unhappy about the visit. Emily Thornberry, the opposition Labour Party's shadow foreign secretary, said Trump had "systematically assaulted all the shared values that unite our two countries". And Labour Party leader Jeremy Corbyn has said he will boycott Trump's state banquet at Buckingham Palace, in protest against his "racist and misogynistic rhetoric".

But, despite the negatives, Trump has much to look forward to.

Queen Elizabeth II will greet him and his family during a ceremonial welcome in the palace's gardens that will be attended by Prince Charles and Camilla, the duchess of Cornwall.

The queen has hosted a raft of US leaders during her 67-year reign, including Dwight D. Eisenhower, John F. Kennedy, Richard Nixon, and Ronald Reagan, but she has only afforded the honor of an official state visit to three; Trump, George W. Bush, and Barack Obama.

Trump will also be front and center at historic celebrations to mark the 75th anniversary of the D-Day landings.

And he will visit Downing Street for talks with May, who said in April, when the state visit was announced, that it would be an opportunity for the UK and the US "to strengthen our already close relationship". She will likely be hoping now that he resists any further temptation to criticize her decisions or endorse her prospective replacements.

The Trump family, which ABC News says will include the president's adult children and their spouses, will return the royals' hospitality by hosting a dinner at Winfield House, the London residence of the US ambassador, before leaving for France, where D-Day commemorations will continue.