The firework display is the highlight of London's official millennium celebrations, which will start at 11am, as dawn breaks over Australasia and continue until the following morning.
Organisers said yesterday that they were expecting up to two and a half million people to flood into the capital for the pounds 3m party, and promised an event that everyone will want to tell their grandchildren about.
In addition to the biggest firework show ever seen in London, there will be a "global village" celebrating the arrival of the millennium in different parts of the world, fairgrounds, dancers, trick cyclists and concerts as well as an Elizabethan street fair near the Globe Theatre with ox roasts. Huge television screens will beam live images from cities around the world. Nick Raynsford, the Minister for London, said: "London's millennium night will be an exciting mixture of spectacular effects and on-going entertainments and fun throughout the day and night."
The giant street party will be concentrated along both banks of the river Thames between Tower Bridge and Vauxhall Bridge.
At one minute to midnight the four faces of Big Ben will be lit up as the countdown begins, and as the first chime sounds a burst of fireworks will be detonated on the Meridian Line at Greenwich, where the Queen and the Prime Minister Tony Blair will be celebrating in the Dome.
Michael Lockett, the chairman of the event, said: "Approximately 18 seconds after the first explosion, the Millennium Moment arrives at Tower Bridge and the first of 2,000 symbolic pyrotechnic candles is set off.
"In 10.8 seconds, the world's biggest ever sequential firework display will speed from Tower Bridge to Vauxhall Bridge. This is the same rate at which the earth revolves on our latitude. We will spiritually rotate with the planet into the New Millennium."
After the final chime the river will fall silent and then a 15-minute firework display which will be visible from outer space will begin. Although London Underground has yet to reach a deal with its staff over plans for working on New Year's Eve, Mr Raynsford said he was confident that transport would not be a problem on the night.
All police leave has been cancelled for the period and Ian Johnston, Assistant Commissioner of the Metropolitan Police, said there would be around 5,000 officers on the streets at a time, double the number who attend the Notting Hill Carnival.
More details for the event are to be announced in the autumn but the organisers, Big Time, said they were hoping to create an outdoor skating rink in Trafalgar Square. Mr Lockett said: "It [the event] will be enormous, immense, electric, like nothing Londoners have ever seen before."