A High Court judge gave his approval on 2 May 2003 for the £600million extension.

Mr Justice Collins said there can be no justification for any further delay to the plans, which have been beset for more than two years by legal challenges from protesters fighting to save the historic viaduct from demolition.

Although finding that the project should have been subject to a local authority planning agreement, he said there had been substantial compliance with planning rules and council backing can and should be swiftly reconsidered.

He added: It is difficult to see how it could conceivably be said that the desirability of retaining the goods yard should outweigh the need for an immediate progression of the Tube line extension.

Protesters had obtained an injunction after Hackney and Tower Hamlets councils gave London Underground the go-ahead.

Peter Boxell of the Strategic Rail Authority said work could start on demolishing the yard within a couple of weeks.

He said: The decision is critical because if we get any more unnecessary delays the project is in deep jeopardy.

The extension will link the line to Dalston Junction and create four new stations.

London's official passenger watchdog, the London Transport Users Committee immediately welcomed the High Court decision to back planning decisions of both Tower Hamlets and Hackney Councils. LTUC called for an immediate indication of support from Government.

Its leader Suzanne May said: It's great that this planning hurdle has been passed, but it’s now time for the Government to get on board the East London Line Extension and give a clear commitment to back this project with funding.

This Committee and its predecessor, the London Regional Passengers Committee (whose remit was limited to passenger transport), have been active supporters of both the northern and southern extension to the East London Line for many years.

The line will create a vital non-road based public transport link to the north and south of the Thames where none now exists. The extensions will provide many more journey opportunities to many Londoners who either would prefer to use public transport or have no other alternative.

We believe that the transport case has been made and that there is considerable passenger demand for this link.

The proposal uses, largely, previously used railway infrastructure and as such will be good value for money.

Hackney Mayor Jules Pipe said: Hackney is the only inner London borough north of the Thames without a Tube. 

Information from the London Transport Users Committee. Press contact: Rufus Barnes Tel: 020 7505 9000) Chair: Suzanne May OBE Director : Rufus Barnes