LONDON (AFP) - More than 2,000 demonstrators rallied in central London Sunday to protest US President George W Bush's visit here at the end of a European farewell tour, police said. "George Bush: terrorist," shouted the protesters, gathered peacefully in Parliament Square a couple of hours before Bush was due to dine with Prime Minister Gordon Brown in nearby Downing Street. Earlier Sunday, protesters demonstrated outside Windsor Castle, southwest of London, where Bush started his British stay in talks with Queen Elizabeth II. Some 1,200 police were deployed or on standby in central London, said a Scotland Yard spokeswoman, who put the number of protesters at between 2,000 and 2,500. The demos were "noisy but peaceful" and no incidents were expected, but they had planned for every eventuality, she told AFP. Scores of policemen, some armed, were backed by rows of police vans on Whitehall, the main government thoroughfare which links Parliament Square to Trafalgar Square. The rally was organised by the Stop the War Coalition, the Campaign for Nuclear Disarmament (CND) and the British Muslim Initiative. "George Bush is on his way out," said Paula Mitchell of the Socialist Worker Party, which is part of the coalition. "He as an individual is not that significant but it's what he represents," she added. "Whoever replaces him in the US is going to carry on with the same policy. They're preparing to install themselves in Iraq semi-permanently. It's turning Iraq into a colony while thousands of people continue to die." Nigel Green, wearing a Give Peace a Chance badge and giving out Socialist Worker leaflets, told AFP: "Obviously we are all looking forward to the day he leaves office. "But I think that it's not guaranteed that the American and British troops are going to leave Iraq or Afghanistan."  Asked if anger over Iraq had calmed, he added: "No, if anything it's as bad as it ever was." Veteran protester Brian Haw, who has manned a permanent peace protest in Parliament Square for over seven years, was greeted with whistles and cheers when he went on stage. "What is going on is so inhumane," he told the demonstrators. "How are we ever going to clean up this mess?" he asked, to applause. Agencies add: Bush arrived in Britain on Sunday for talks with Prime Minister Gordon Brown on Iran and other issues, as both sides vigorously denied any rift over troop levels in Iraq. The US President's visit was the penultimate stop on his European farewell tour before leaving office in January. Bush, flying in from France, enjoyed afternoon tea with the Queen at Windsor Castle as he ended his 'farewell tour' of Europe by visiting the UK. The US leader and his wife Laura sat down with the monarch and the Duke of Edinburgh for the informal gathering in the lavish setting of Windsor Castle. Afternoon tea with the Queen is in stark contrast to the serious discussions the President will hold with Brown. Bush has already urged the Prime Minister not to jeopardise coalition gains in Iraq by the premature withdrawal of British troops. In an interview with The Observer newspaper, the US leader said there should be no "definitive timetable" for troop reductions. He will head to Northern Ireland on Monday (today), his last stop before flying home. Even before Bush's presidential Air Force One airplane touched down at London Heathrow, top officials dismissed a report in The Observer newspaper that suggested he would warn Brown against a premature withdrawal from Iraq. "There is no disagreement between us, between the President and Prime Minister Brown, on this issue, period," US National Security Adviser Stephen Hadley told reporters. The two agree that any withdrawal "has to be a result of progress on the ground, on the advice of our military, and not according to any arbitrary schedule," said Hadley. Another US official branded the report "ludicrous". A Downing Street spokeswoman told AFP that there was "absolutely no disagreement" with the United States over the issue. Hadley said the talks would focus on tightening sanctions on Iran over its refusal to freeze its suspect nuclear programme - a subject Bush said on Saturday had "dominated" his European tour thus far. "That (sanctions) seems to be pretty clear commitment and consensus throughout Europe," the adviser said. Both sides said the talks would also include climate change, the state of the global economy and ongoing efforts to clinch an international trade liberalisation deal. "Brown is a different personality than Blair. The president, I think, has forged a good, close relationship with each and both of them," said Hadley. "And, of course, what underlines that relationship is the fact that the United States and Britain continue to have a very special relationship," he added. Bush's last high-security visit to London, in November 2003, saw three full days of protests, with tens of thousands of people marching past Downing Street marshalled by 5,000 police officers. The Stop the War Coalition, which wants full British withdrawal from Iraq and Afghanistan, is planning vocal protests in London and Windsor, again urging Bush's arrest for war crimes and opposition to US pressure on Iran.