Thousands of anti-Trump protesters descended on London this afternoon, holding giant balloons of Donald Trump in a nappy and waving effigies.Large crowds marched on Westminster, packing Parliament Square, as the US President and his wife Melania were hosted by the King and Queen at Windsor Castle.The event was initially billed as a demonstration by the Stop Trump Coalition of 50 organisations, angry that the UK was again hosting the veteran Republican.But the protest quickly took on the feel of a pro-Palestinian march, with chants of 'free, free Palestine' and the distinctive black white green and red flag seeming to outnumber anti-Trump banners.It was a much more sedate affair in Windsor, where just a handful of protesters braved the dreary September weather to make clear their opposition to President Trump, who has historically aligned himself strongly with Israel.Indeed the smattering of demonstrators outside the Castle were outnumbered by the world's media and a large police presence.Thames Valley Police put large barriers in place as part of security measures, with the entirety of the two-day state visit taking place behind closed doors, at Windsor Castle and at Sir Keir Starmer's countryside residence Chequers, where the Trumps are due visit tomorrow.Meanwhile, 25 miles east of Windsor in central London, one activist made their feelings known by dragging an effigy of the President. A protester in central London carried an effigy of US President Donald Trump in a Make America Great Again cap Thousands of people walked through the capital in a protest designed to oppose the Republican's state visit - but there was a distinctly pro-Palestine feel The crowds arrived on Parliament Square shortly after 4pm Meanwhile, only a handful of people turned up outside Windsor Castle - where the President and his wife Melania are guests of the King and Queen - to make their objections known The march in central London closely resembled a pro-Palestine march, with flags, banners and chanting supporting Palestine A protester holds a 'Trump Baby' knitted toy on the march through Westminster, while another holds an inflatable version Reform UK leader Nigel Farage - whose name appeared on some banners - was booed when he was referenced by speakers on Parliament Square Artist Kaya Mar, pictured with a Trump cartoon, was one of the few protesters present outside Windsor CastleBut the numbers were swelled by demonstrators from left-wing groups including Amnesty, the Palestinian Solidarity Campaign and Stop the War, who waved Palestinian flags and chanted 'Stop the hate, stop the fear. Donald Trump's not welcome here' and '1234 Occupation no more. 5678. Israel is a terrorist state'.Campaigners marched from near the BBC's Broadcasting House in Portland Place to Parliament Square while holding signs which stated: 'End the genocide. Stop Trump' and 'Resist fascism. Resist Trump'.Some protesters carried smaller versions of the Trump baby blimp, which became a symbol of demonstration during the President's first UK state visit in 2019.One man - who arrived at the march dressed up as Israeli Prime Minister Benjamin Netanyahu - held up a sign stating: 'War criminals for Trump'.Rosemary Strivens, 70, who arrived wearing a Palestinian neck scarf known as a keffiyeh, said: 'We hate what is happening in America with Trump.'We feel that democracy is threatened.'Black people. Women. Immigrants. They are all threatened in America.'We think he (Trump) is scum. Left-wing singer-songwriter Billy Bragg performed for crowds at the anti-Trump march in Westminster Zarah Sultana, who is forming a new political party with ex-Labour leader Jeremy Corbyn, also gave an address to crowds Some of the banners described President Trump as a fascist 'I feel that Trump could bring to an end the genocide in Gaza and he hasn't done anything.'Protesters arrived at Parliament Square shortly after 4pm, and featured a number of speeches in which references to Reform UK leader Nigel Farage, and former Trump ally Elon Musk were met with boos from those assembled. Veteran singer-songwriter Billy Bragg performed for the crowds, while former Labour leader Jeremy Corbyn, and Zarah Sultana, who have formed a new political party, also spoke.New Green Party Zack Polanski leader said the President Trump's second state visit was 'absolutely outrageous'.Speaking at the rally, attended by up to 5,000 people, according to the Metropolitan Police, said: 'Of course, we should have a relationship with the American president who's democratically elected, but to give him a state visit, millions of pounds spent on security, a red carpet, the pomp and ceremony of everything that's happening - that's absolutely outrageous.' 'What we're seeing is this rolling out the red carpet for a man who absolutely does not represent British values.'A handful of counter protesters - including members of Turning Point UK - also tried to engage with anti-Trump activists.Two people were arrested in Windsor for incidents linked to the state visit, Thames Valley Police said. A 56-year-old woman, of no fixed address, was arrested on suspicion of assaulting an emergency worker and using threatening or abusive language, while a 36-year-old man, also of no fixed address, was held on suspicion of public order and assault. Further, smaller protests are planned outside parliamentary buildings across the four nations tomorrow and Friday.