The US president's visit will be the UK's most intensively policed event, London's force said on Monday.
The Metropolitan police, which has cancelled all leave for the state visit that starts when George W. Bush flies into Heathrow on Tuesday evening, has raised the number of shifts worked by officers from 5,000 to 14,000 during the four days he is in London.
About 1,300 police will be on duty when Mr Bush visits Sedgefield, the prime minister's constituency, on Friday. Protesters against the war in Iraq are planning a substantial demonstration to greet Mr Bush when he arrives in the north-east. Mr Bush will be taken straight to Buckingham Palace on Tuesday evening where he will stay as a guest of the Queen for two nights.
On Thursday he will lay a wreath at the tomb of the Unknown Warrior in Westminster Abbey before talks with Mr Blair at Downing Street. Police are already on an increased state of alert but the Home Office stressed on Monday there was "no specific threat" and the "public should continue to be alert but not alarmed".
The Metropolitan police said there would be no traffic disruption outside the central London areas of Victoria, Westminster, Whitehall and Trafalgar Square. Roads closed for specific events would be reopened as soon as possible afterwards, and no roads would be completely sealed off. London Underground would also operate normally.
Police dismissed suggestions that the M4 from Heathrow to London would be closed and said it was more likely the president would travel to the palace by helicopter. The centrepiece of the planned protests is a march from Malet Street to Trafalgar Square on Thursday.
The joint organisers, the Stop the War Coalition, the Campaign for Nuclear Disarmament and the Muslim Association of Britain, are expecting upwards of 60,000 people to take part - not as high as the 1m-1.5m that marched against the war in February but unprecedented for a weekday.
The protesters on Monday claimed a first victory when the Met dropped its objections to their marching along Whitehall. The rest of the route has still to be agreed but police had earlier wanted the marchers to stay clear of the Houses of Parliament. Other protests are planned on Wednesday and Friday in London and in cities around the country. The protests started early when a middle-aged woman climbed the gates of Buckingham Palace on Monday and waved a protest banner. She was later arrested.
Charles Kennedy, Liberal Democrat leader, backed the planned protests, and said he would raise concerns over the war and the UK nationals held without charge at the US naval base in Guantanamo Bay, Cuba, when he meets the president on Wednesday. Pupils have been warned they face punishment if they play truant and attend protests.