Road and rail links in Kent and London could be "significantly impacted" if current travel plans for a multi-billion pound theme park resort go-ahead, it is claimed.

Bosses behind the £2.5bn London Resort based on the Swanscombe Peninulsa have been urged to rethink transport assessments amid concerns raised over the resilience of the Dartford Crossing.

In written submissions to The Planning Inspectorate, various transport bodies have criticised the park's methodology for assessing its impact on key travel corridors.

They warn that existing and future infrastructure in London and Kent could be overwhelmed if sufficient mitigation is not offered.

Highways England, which is steering forward a separate proposal for the Lower Thames Crossing at Gravesend, claimed the Resort's assessment of transport impacts remained incomplete with "insufficient information" from which conclusive statements could be drawn.

Locations of potential concern include M25 junctions 2 and 30, the A13/A1089 junction and the A2/M2 east of the M25.

Transport for London (TfL) also hit out at a perceived lack of an "appropriate assessment methodology", claiming this could potentially hide "significant impacts that must be mitigated".

It comes amid warnings that key routes such as the Dartford Crossing could be severely impacted should the proposals be given the green light.

Even in so-called “without Lower Thames Crossing” scenarios, TfL claims the proposals could lead to a sizeable diversion of traffic onto its own road network at the Blackwall and Silvertown tunnels in East London.

TfL told government planners: "An incident on the Dartford Crossings or delays on the HS1 rail lines, for example, could lead to a significantly different pattern of demand.

"Since such incidents are relatively common, especially on the Crossings, it is reasonable for those effects to be considered."

London Resort's 25,000-page application was accepted for examination in January.

Inspectors from the government's Planning Inspectorate have been tasked with deciding the bid, known as a development consent order (DCO).

Interested parties, community groups and residents were invited to submit their views on the plans to be heard during a series of public hearings over the coming months.

A list of "relevant representations" were published on the government planning arm's portal last week after the deadline for comments elapsed.

In further written submissions, concerns were also raised by the C2E Partnership regarding the development's potential impact on a mooted Crossrail extension to Ebbsfleet, as well as local bus links.

This included required upgrades at Swanscombe station and Fastrack bus services in Dartford.

The taskforce also hit out the park planner's modelling which it claimed was incomplete at the time of submission, meaning an assessment of the full impact on the rail network was not possible.

It said: "The safeguarding and future proofing measures required for an extension of Crossrail should be secured through the DCO and they are not included at present."

Theme park bosses says they are currently in the process of reviewing all the submissions.

“The relevant representations have only just been published and we look forward to working our way through them with the organisations and the Planning Inspectorate,” said London Resort's strategy and communications director Andy Martin.

London Resort says it will create a new access road from the A2 in addition to new ferry services.

As part of its transport plans it proposes that 25% of car passengers should travel via a new ferry terminal between the theme park and Tilbury, Essex. Other visitors would be expected to travel by boat from central London.

The planning bid outlines the need for seven new 400-seat ferries to deliver this service with additional piers if required.

Earlier this month the BBC's studio arm, which has struck image rights deals with the park, was urged to withdraw from the project amid claims of incompatibility with its aims of "creating a positive environmental impact".

It comes after the Swanscombe Marshes were designated as a site of special scientific interest (SSSI) following a campaign led by locals and national wildlife organisations.

The status granted by Natural England – the government's environmental advisory group – means any future development plans must take into account the abundance and important wildlife in the area.

But bosses say their plans will enhance and further protect the biodiversity of the brownfield site.

Yesterday they announced further sustainbility plans for an additional section of the former cement works to serve as a "prehistoric nature reserve".

The zone will include educational opportunities for kids, as well as roaring rollercoasters and treetop ziplines.

Resort bosses also requested more time to review what it called its "gold standard" case for sustainability.

"Working with the Planning Inspectorate, we have requested further time to prepare for the formal enquiry later this summer,” said chief executive PY Gerbeau.

“It is absolutely fundamental for us to be leaders in sustainability. We’ve already committed to spending around £150m on remediation, habitat enhancement and providing around 8 miles of footpaths and public rights of way."

The Planning Inspectorate has appointed a panel of four members to review the proposals.

Leading the inspection is Stuart Cowperthwaite, who will be joined by Simon Warder, Deborah McCann and Richard Jones as members of the examining authority.

It is expected the process will last for a duration between 12 and 18 months.

Read more: All the latest news from Dartford

Read more: All the latest news from Gravesend