A Donald Trump baby blimp has taken to the skies as organisers expect thousands of people to line London's streets to protest against the state visit of the US president.
The 20ft orange inflatable was flown on Tuesday morning after its owners reached their fundraising target and permission was granted by the Greater London Authority.
A team of organisers wearing red jumpsuits and hats marked "Trump Babysitters" launched the balloon to cheers from dozens of onlookers at Parliament Square, where nearby roads are sealed off and police are standing guard in anticipation of large protests.
Shaista Aziz, from the Stop Trump coalition, said the blimp of the nappy-clad president clutching a mobile phone has "captured the world's imagination".
"We know that this will definitely annoy Trump," she said.
"It helps us shine a light on the very serious issues around this Trump presidency."
Organisers of the Together Against Trump protest have billed it as a "carnival of resistance", with demonstrators gathering at Trafalgar Square from 11am to declare a "Trump-free zone".
A 16ft talking robot of Mr Trump sitting on a gold toilet, which says the phrases "No collusion", "You are fake news" and "I'm a very stable genius" – the audio of which is Mr Trump's own voice – is attracting onlookers.
Climate change activists, students, pacifists, trade union members and families are expected to gather, while the protesters will include Handmaids Against Trump – women who will be draped in red with white hoods in homage to Margaret Atwood's dystopian novel about a crackdown on reproductive rights.
A huge police and security operation is under way, with protesters barred from demonstrating directly outside Downing Street and road closures in place.
Labour leader Jeremy Corbyn will address those demonstrating against Mr Trump's policies on the second day of his visit.
Mr Corbyn, who refused to attend a state banquet on Monday evening for the president, said he will join crowds to "stand in solidarity with those he's attacked in America, around the world and in our own country".
Labour's Diane Abbott and Emily Thornberry confirmed their attendance, while the Liberal Democrats and Green Party are appealing for the public to join them.
TUC general secretary Frances O'Grady and Mark Serwotka, head of the Public and Commercial Services union (PCS), will also speak to those gathered.
Trump supporters are also taking to the streets.
Lewis Metcalfe, 28, from Richmond in North Yorkshire, said he took a day off work to travel to London and offer "a difference of opinion".
"I'm obviously going to be a minority today. I'm not here to troll, to cause a riot or cause disruption," said Mr Metcalfe, who was at Parliament Square wearing a Make America Great Again cap.
"I don't agree with all his policies. He's not the greatest president in the world but he does get things done.
"I think it (the protest) is a little bit hypocritical because you get hundreds of thousands of people for Donald Trump today and yet we had minuscule, maybe hundreds of people, for Xi Jinping and Mohammed Bin Salman."
Demonstrators will not be permitted to march past Downing Street as part of Whitehall will be closed off.
Crowds will stop at the north end of Whitehall and proceed to Parliament Square by an alternative route.
The Metropolitan Police said a "barrier plan" will be in place across part of Whitehall just north of the Women's War Memorial.
Scotland Yard's Deputy Commissioner Sir Steve House told the London Assembly Police and Crime Committee on Tuesday the policing plan has so far worked "effectively".
He said the force is not in a position to estimate how much the operation will cost but added the US president's last visit to the capital cost the Met about £2.9 million.
Around 250,000 anti-Trump activists gathered when he visited the UK as US president for the first time on July 13 last year, with the blimp making its maiden flight.
Elsewhere across the UK, protests are also planned in Birmingham, Stoke, Sheffield, Glasgow, Edinburgh, Chester, Leicester, Oxford and Exeter.
On Monday, several visual protests were staged as the president touched down on British soil.
Amnesty International unfurled five banners on Vauxhall Bridge in view of the US embassy in London.
And a projection of Mr Trump's UK approval rating on the Tower of London was organised by anti-Brexit protest group Led By Donkeys.