Nearly two million people signed a petition demanding he be banned from the United Kingdom because they believe he is sexist and racist and "Stop Trump" campaigners say he will face a "Wall of Sound" outside all the landmarks he visits because supporters will bang pots and pans.
"I'm going to a pretty hot spot right now, right?"
"The people voted to break it up, so I imagine that's what they'll do".
Matthew Butcher, an anti-Trump campaigner and one of the "babysitters" of the balloon, said: "I think that the thing that the Trump balloon does is that it brings an element of fun to the protests, but it also gets under Donald Trump's very thin skin".
Supporters of Brexit say such a trade deal with the world's biggest economy would be one of the great benefits of exiting the bloc.
Trump is technically on a lower-level working visit this week.
"There is no stronger alliance than that of our special relationship with the United States and there will be no alliance more important in the years ahead", the British leader said.
"This week we have an opportunity to deepen this unique trading relationship and begin discussions about how we will forge a strengthened, ambitious and future-proof trade partnership".
May has had to defend Trump's visit in the face of fiery criticism from opposition lawmakers. It will hover above Parliament Square later this week during the president's visit.
Gardner, who works with refugees as part of her doctoral research at the London School of Economics, said Trump's speeches about refugees and immigrants are "a very unsafe line of rhetoric to be normalized".
"I've been reading a lot about Brexit over the last couple of days and it seems to be turning a little bit differently where they're getting at least partially involved back with the European Union", he told reporters. "I warned them. Immigration is taking over Europe". A baby-shaped Trump balloon is expected to fly over Parliament on Friday morning. Tens of thousands are expected to flood the streets in protest.
A number of protests have been planned for the president's stay in the country, with the largest march due to be held in London on Friday.
After taking a firm stance both days of the conference, which included calling Germany a "captive" of Russian energy, Trump did say US commitment to North Atlantic Treaty Organisation remains strong and he thanked other members for "additional money they are putting up".
May will seek to put the tensions behind her when she hosts Trump later Thursday for a black-tie dinner with business leaders at Blenheim Palace, the birthplace of World War II prime minister Winston Churchill.
British Prime Minster Theresa May and U.S. President Donald Trump walk across the courtyard at Blenheim Palace, where they are attending a dinner with specially invited guests and business leaders, near Oxford, Britain, July 12, 2018.
Over a lunch of Dover sole, lamb and lemon meringue pie, the leaders will discuss Russian Federation, trade, Brexit and the Middle East.