By May 2012 commuters will be able to travel from Clapham Junction to Docklands in 20 minutes, after the Government and the Mayor of London finally agreed funding for the phase two extension of the East London Line.

The scheme - costing £75 million - will link Clapham Junction to Surrey Quays, with direct links to the City and Docklands.

The announcement will raise a smile on the faces of Battersea's 1,800 down-trodden rail commuters - who currently have to travel through town to get to Docklands - and should make Wandsworth more attractive to investors and city workers.

Mayor Boris Johnson welcomes the scheme

The project, due to be completed in time for the Olympics, will ease pressure on the Tube and roads, Mayor of London Boris Johnson said, and will complete London Overground's orbital rail system - meaning passengers will be able to travel around the capital without the need to navigate through the centre.

The Department for Transport has provided £64 million for the project, with TfL contributing the remainder.

Mr Johnson, who had been joslting with the Government for funding, said the news was “tremendous”.

He said: “What it means is that people in the area can move around much more easily to economic centres and the Docklands.

“We are predicting 11 million journeys on the network and we are going to reduce the number of car journeys by 220,000. It has got to be good for the environment and for people.”

He added the project would make Wandsworth much more attractive.

“Transport is the key to liveability if you can move around more conveniently then it makes an area much more attractive for people to live in and invest in, ” he said.

“Business also has the confidence that they can invest in this area in the knowledge they will have fantastic communications all around in an orbital route. It also means people in the Docklands will know that the 1,800 people who live in Battersea will have a much smoother journey to work.”

Battersea MP Martin Linton, who had been campaigning for the extension for more than 10 years, said the announcement was a “relief”.

“The huge benefit is that Clapham Junction will be on the Tube map by 2012,” he said. “Clapham Junction has been waiting to be on the link to the tube system for 100 years . . . its a great moment for Clapham Junction and it is going to be a great revolution for commuters and for local people.”

Transport Secretary Geoff Hoon said the investment was timely. He said: “There is both a long term argument that this part of London has not had the same access to public transport as north London for example, particularly access to the Tube and there’s a shorter term argument to ensure that once the recovery comes we will be able to take advantage of that and move people and businesses around more easily, particularly around this congested part of south London.”

Guy Senior, Wandsworth Council’s transport spokesman, said: “This is great news, Wandsworth and other south London boroughs have been campaigning for this for years. This will also help the population growth forecasted for this part of London.”

The Conservative’s parliamentary candidate for Battersea, Jane Ellison, added: “It is a good example of what can be done working constructively together . . . it is excellent news.”

Peter Pledger, chief executive of South London Business - which represents companies in south London - said the extension was good news for jobs and the economy and “would put thousands of residents and businesses on the tube map”.

He said: “The extension provides a rare East - West Link in South London helping businesses and residents to move across South London without having to go into Central London.

“It has been a long wait for tube developments in South London: after the Victoria line got to Brixton in 1971 we had to wait until 1999 to get the completed Jubilee Line from Waterloo to Canada Water. Now with the first East London line extension to West Croydon due to open in 2010 and this announcement we are beginning to see real positive change for South London.

“Such a development will also help business see out this recession as it will increase access to many areas in Wandsworth, Lambeth, Southwark and Lewisham and help businesses attract new customers.

Transport investment is often a real stimulus for regeneration and I believe that this development will help to drive economic growth from Clapham to Surrey Quays.”