Tunnel recommended for new Thames crossing
A new tunnel should be built underneath the Thames east of Gravesend to tackle congestion, according to the leader of Kent County Council (KCC).
Three locations have been put forward as possible sites for a new bridge or tunnel crossing between Kent and Essex.
KCC leader Paul Carter said the council backed option C - connecting the M2 in Kent with the A13 and M25 in Essex.
Thurrock and Dartford councils want to see the effect of the removal of toll barriers at the existing crossing.
Barriers at the Dartford Crossing will be removed from October next year and motorists will be charged via number-plate recognition cameras.
The Highways Agency has said the "free flow" system will improve congestion.
Mr Carter said: "I have enormous empathy with those who will live close to the link roads or what will eventually be the third Thames crossing, but I have to act in the best interests of the greater residency of Kent and the motorists of Kent."
"I passionately believe that a third Thames crossing is needed."
The existing Dartford to Thurrock crossing, which consists of the QEII Bridge and a tunnel, is used by 140,000 vehicles a day.
John Kent, leader of Thurrock Council, said: "I fear that if you build another bridge or another tunnel in the east of the borough all you'll do is replicate the problems of the west in the east - and everybody in the middle will be stuck in a hideous pincer movement."
"If you do away with the tolls, you free up extra capacity on the crossing.
"I think you'll find you have enough capacity to improve things beyond the point where you need a new crossing."
Three crossing options
The government has said a new Lower Thames road crossing, costing up to £5bn, was necessary to tackle congestion.
Option A is the site of the existing Dartford to Thurrock crossing, option B would connect the A2 with the A1089, while option C would join the M2 in Kent with the A13 and M25 in Essex.
Option C, the most expensive, would pass through undeveloped green belt land including Kent Downs Area of Outstanding Natural Beauty, ancient woodland and the Thames Marshes.
The other options would cost between £1.2bn and £2.2bn, according to estimates.
Natalie Chapman, of the Freight Transport Association, said: "We think there is a need for an additional crossing.
"When free flow comes in at the end of next year that's going to really help the current congestion problems, but what we need to look at is much further in the future."
Jeremy Kite, the leader of Dartford Borough Council, said the authority wanted to let the free-flow tolling take effect, but that its preferred option was C.
"We need to find a solution. It's about finding the right solution for Britain," he said.
"I do think it's a shame the government isn't consulting on other options.
"It is murderously more expensive the further down the estuary you go, but if we are really in this for the long haul surely what we should be doing is looking for the right results."
Richard Knox-Johnston, from CPRE Protect Kent, said: "Maps produced by the Environment Agency show flooding areas when sea levels rise by 1m.
"You've got to take this into account in an planning."
John Burden, leader of Gravesham Borough Council, said: "Option C is the one we least want.
"We need to look at the long term needs for the area. I don't think options A, B or C offer the solution.
"We need a proper managed transport solution."