The Mayor's office says that the Northern Line extension will reduce pressure on Vauxhall station and existing Northern Line services, in addition to boosting the area's economy.
It is expected that work on the line could begin by 2015, with services in operation by 2020.
A consultation on the plans is already underway.
More top news
Arsenal managed to beat Everton at the weekend but it wasn't enough to finish in the top for the first time in Wenger's time at the club.
The entertainer was held for the murder of Stuart Lubbock, who was found dead in his swimming pool in 2001, but never charged.
Although the diamond was believed to be cut in the 19th Century, its history and how it arrived at the car boot sale is unknown.