Demonstrations come as May welcomes president to Downing Street

Large crowds gathered in Trafalgar Square in central London on Tuesday to protest against US President Donald Trump's visit to the United Kingdom.

Trump and his entourage arrived in the country on Monday and spent the day on ceremonial duties, before the political aspect of his visit began on Tuesday with a meeting with outgoing Prime Minister Theresa May, who is resigning at the end of this week.

Just down the road from her Downing Street office where that meeting took place, thousands of protestors assembled for a demonstration against Trump's visit, which included speeches from various people including Labour Party leader Jeremy Corbyn, who declined an invitation to dine with Trump during his visit. Also nearby in Parliament Square, the famous Trump Baby Blimp, created for his visit to the country last year, was once again flying.

Trump's visit comes at a delicate time in British politics, with the country's relationship with its closest neighbor and economic partner, the European Union trading bloc, in turmoil following three years of failing to make progress on the topic of how Britain will leave. This impasse has caused May's downfall, and there is now a desperate race among Conservative members of Parliament to succeed her as party leader and prime minister.

The first issue the new leader faces is how to prepare for Brexit, currently scheduled for Oct 31, and many leading contenders, including the Trump-endorsed Boris Johnson, have spoken of their willingness for a no deal-Brexit, which means leaving with no alternative economic or legislative arrangements in place.

Trump favors such an approach, suggesting it could earn the UK favorable trading terms with the US. And in a BBC interview on Sunday, when asked specifically about how such a deal would impact on the country's free at the point of delivery National Health Service, the US Ambassador to London Woody Johnson said "I think probably the entire economy, in a trade deal all things that are traded will be on the table."

On Wednesday Trump will attend commemorative events for the 75th anniversary of the D-Day landings in Normandy in Northern France, one of the pivotal events of World War II. The Queen presented him with a rare Winston Churchill book about the war, and in her speech on Tuesday, Prime Minister May spoke of the two countries' so-called special relationship, "a great partnership, but one I believe we can make greater still".

Continuing the historical theme of the visit, she gave Trump a framed typescript draft of the Atlantic Charter, agreed by Churchill and President Roosevelt in 1941, setting out the two leaders' postwar aims and paving the way for the formation of the United Nations. Some observers have suggested that this is a message with two meanings, given Trump's attitude toward the UN and its work.

In the run-up to the Downing Street meeting, US Secretary of State Mike Pompeo increased pressure over the possible future role of Chinese mobile phone company Huawei in the British telecoms network by repeating doubts about how secure its systems are.

In April, following a meeting of the National Security Council, May decided to allow Huawei to be partially involved but it was a disputed decision, and several of the candidates to succeed her as prime minister have already expressed their reservations about it.

Speaking in the Netherlands, Pompeo said he urged "our allies and our partners and our friends, don't do anything that would endanger our shared security interests or restrict our ability to share sensitive information."

However, some say US criticisms are commercially driven, as part of US-China trade tensions, rather than based on security fears. British government sources have indicated that no final decision on Huawei will be made this week, which would mean it would be the responsibility of whoever ends up succeeding May in Downing Street.