Tower Bridge is to get a facelift, a 4 million pound project that will take four years to complete.

The 114-year-old bridge, whose middle section can be raised to let tall ships pass up and down the river, will be repainted its traditional blue and white, a task that will require 44,000 man hours and 22,000 litres of paint.

"As one of the world's most iconic and internationally recognised landmarks ... the smart appearance and imposing grandeur of Tower Bridge resonates strongly with national pride," the City of London said as it unveiled the project.

The 60-metre bridge (200 feet) will be painted in sections to try to minimise the disruption caused, but it will still have to be entirely closed for at least two months during 2010.

Tower Bridge, which opened in June 1894 and gets its name from the nearby Tower of London, is used by around 40,000 motorists and pedestrians every day, making it one of the busiest of London's many river crossings.

The bridge used to be raised up to 50 times a day to let tall ships pass underneath, but now is raised only around 1,000 times a year and on ceremonial occasions.