A council has "significant" concerns with a multi-billion pound 14-mile tunnel which will cut through the Kent countryside.

Thurrock Council, on the Essex-side of the River Thames, has written a letter to the Treasury saying the Lower Thames Crossing project needs to be re-evaluated as it will not achieve its stated aims.

The tunnel, estimated to cost £8.2bn, will stretch under the River Thames and connect Kent and Essex.

Plans have been discussed for more than a decade and it is estimated to open between 2029 and 2030.

In his letter to Simon Clarke, Chief Secretary to the Treasury, Rob Gledhill, Conservative leader of the council, expressed the need for a reassessment as there are "significant and exceptional domestic and international challenges and events over the preceding three years".

He said: "The council's concerns are exacerbated by poor engagement by National Highways, especially in relation to sharing key information about local impacts.

"The council contests that insufficient evidence has been presented to demonstrate that there are scheme benefits that outweigh these impacts."

Chris Stratford, who has been advising the council's Lower Thames Crossing Task Force, added the five-and-a-half-week public consultation had been launched prematurely as they have only just received the operation and construction traffic modelling.

He also said air quality, health impact and noise assessments were still outstanding.

Consultation on the plans ended on June 20.

But Mark Bottomley, development director for the Lower Thames Crossing, said tens of thousands of people face challenges at the Dartford Crossing, and must have their needs addressed.

He said the crossing would almost double road capacity across the Thames east of London to ease congestion at Dartford.

Mr Bottomley told the BBC: "The Community Impacts Consultation held last year contained comprehensive information on air quality and health broken down area by area."