It comes as Highways England is set to launch a public consultation on the proposals tomorrow (Wednesday 10 October), ahead of making an application to the Secretary of State for Transport for a Development Consent Order (DCO).
Cllr Rob Gledhill, Leader of Thurrock Council, said: "All Councillors remain unanimously opposed to the Lower Thames Crossing, as I have made abundantly clear on many occasions, and that position has not changed.
"Contrary to Highways England's claims that the scheme will enable sustainable local development and strengthen and connect local communities, it will in fact just smash through greenbelt land, damage development opportunities and effectively cut the borough in half.
"There is a clear absence of any real connectivity improvements here, only the threat of a motorway and absolutely nothing that will benefit our residents as has been intimated by Highways England. In fact, this proposal will have a completely unacceptable impact on Thurrock.
"Now we know the full extent of Highways England's plans we will go to any lengths in fighting these abysmal proposals, and I will be calling on all councillors, irrespective of party, to back my motion at full council later this month to go to court for a Judicial Review."
Cllr Mark Coxshall, portfolio holder for regeneration, added: "The way this consultation has been launched without sufficient prior engagement with the council or information from Highways England is entirely inadequate.
"It is publishing consultation documents which run to thousands of pages, yet has refused to provide any information to us in advance. Now we will finally have sight of the consultation materials, officers will carefully review the detail of what is published to ensure we respond quickly and robustly, and can provide information to support the public in responding.
"But whether you were in favour of this option or not, this final proposal bears little resemblance to what was promised and is of no benefit to our borough."
Cllr Peter Smith, Chair of the Lower Thames Crossing Taskforce, said: "Our cross-party taskforce have already achieved some significant successes, including persuading Highways England to carry out a full health impact assessment, and we will continue to fight these proposals in the best interests of our residents.
"We have also agreed 54 mitigation measures which the scheme must deliver and we will now be testing the proposals against these measures to ensure we get the very best outcomes for Thurrock.
"We call on everyone in the borough to have their say in the consultation by both attending one of Highways England’s public information events and, crucially, completing a feedback form either online or in paper form."
The consultation material will be available at www.lowerthamescrossing.co.uk/haveyoursay and runs until Thursday 20 December 2018.
Paper copies of all the consultation documents will also be available at Grays Library and Tilbury Hub during normal opening hours.