Trams would operate on Newcastle's quayside

Initial details of the �1.5bn plan - dubbed project Orpheus - were outlined in July, by Nexus, who operator the Tyne and Wear Metro system.

Now more details have been released, which will see the 23-year-old Metro light railway system effectively replaced with trams and environmentally-friendly busses.

The 15-year project will see rolling stock, track and bridges replaced or upgraded.

It will also see the system expand southwards into County Durham as far as Seaham, south of Sunderland.

The network already covers Newcastle, Gateshead, North and South Tyneside and the city of Sunderland.

A bid for public cash to fund the ambitious project is expected to made to the government in 2004.

'Radical action'

Mike Parker, director general of Nexus, said the plan was a public transport 'revolution' for the north-east of England.

He said: "Critically, project Orpheus will address our pressing need to get people out of their cars and onto public transport.

"Levels of congestion are rising year on year and unless we take radical action we could see traffic hit unmanageable levels within a very short period of time.

"Also, the long term strategy for the reinvigoration of the existing Metro network is crucial to the future of public transport.

"Orpheus will deliver that solution and move public transport in Tyne and Wear into the next era."

Members of the Tyne and Wear Passenger Transport Authority are due to debate the plan next week.