Plans have emerged for a privately owned £600m tram system linking Essex to north Kent through a new tunnel under the Thames.

The KenEx Thames Transit has been proposed to relieve pressure on the congested Dartford Crossing and combat air pollution.

The scheme comes from financial accountant Gordon Pratt who has previously worked with the London and Southern Countries Railway Consortium.

Public transport is estimated to relieve only one per cent of traffic using the Dartford Crossings and campaigners have petitioned to introduce better transport links.

The tram system would have three lines connecting Bluewater, the proposed Paramount Resort and Grays station on the other side of the Thames.

Councillor Keith Kelly, cabinet member for transport and infrastructure at Dartford Borough Council, said more alternatives were welcome.

He said: “My feeling is that this solution would be used by people from the local area, most of the traffic using the crossing comes from other areas.

“I would imagine there would be a number of complications when trying to get this through planning, and from my understanding of infrastructure would say this would cost more than £600m.

“I think an alternatives are welcome but I am not convinced that this is a goer at this time.”

Liberal Democrat campaigners, including James Willis, said a new public transport link would cost 10 per cent of the new Lower Thames Crossing and alleviate between five and 10 per cent of crossing traffic.