The 1970s station, which is one of the oldest on the network, will close from March 2009 and will be one of the longest closures of a central London station.

The £350m revamp will see all eight floors of the station demolished and replaced with a largely glass "airy and cathedral-like" structure.

Balfour Beatty will carry out the works which include lengthening platforms across the Thames, a new entrance on the south bank of the river and the redevelopment of the station.

Once completed, at the end of 2011, the upgraded overground station will able to deal with three times the number of trains and passengers as it does currently-from a maximum of 64 carriages per hour to 172.

It will also be the first station in London to span the Thames - enabling direct access to the South Bank and attractions including the Tate Modern.

The first phase of the Thameslink programme, which will virtually treble passenger capacity from the current 4,500 an hour to 12,000 is scheduled to be completed in time for the 2012 Olympics.