The number of lorries on Blue Bell Hill could double when the Lower Thames Crossing opens.

That's according to Highways England traffic modelling seen by MP for Faversham and Mid Kent Helen Whately.

The £6.8 billion 14.5-mile route linking Kent and Essex is set to be up and running by 2027 and is billed as the solution to the motorist's nightmare that is north Kent and, in particular, the Dartford Crossing.

But we revealed last month none of that money will go towards surrounding roads and Mrs Whately says without investment the network is at risk of collapse.

The modelling also suggests already gridlocked Maidstone could endure a 25% increase in cars.

Mrs Whately brought together 10 Kent MPs to write to Highways England expressing these concerns and demanding 10 urgent improvements ahead of the crossing's opening.

They were: Tracey Crouch (Chatham and Aylesford), Tom Tugendhat (Tonbridge and Malling), Helen Grant (Maidstone and The Weald), Gordon Henderson (Sittingbourne and Sheppey), Adam Holloway (Gravesham), Damian Green (Ashford), Kelly Tolhurst (Rochester and Strood), Charlie Elphicke (Dover and Deal), and Sir Michael Fallon (Sevenoaks).

They said while they welcomed the "economic benefits" the crossing will bring it should not be looked at in isolation.

The letter read: "Changes to traffic flows mean that roads downstream of the crossing must also be improved to avoid gridlock. It is important that upgrades are made to connecting roads in time for the opening of the crossing in 2027."

"The resilience of our roads will be severely tested," it continued, when thousands of homes planned for the county are built.

The letter calls on Highways England to make the following improvements:

A229

The A229 (Blue Bell Hill) should be reclassified as a strategic road and upgraded accordingly.

Even without the crossing it's set for a 10% increase in traffic and once it's opened it's feared as the most direct link between the M20 and A2 it will become a trunk road, doubling the number of lorries using it.

A228

With almost 30,000 new homes planned for Medway by 2035, many of which off the A228, measures need to be taken to make sure junction 1 and 2 can cope and divert traffic away from the road.

M2 Junction 5

Stockbury Roundabout is set for massive improvement in the shape of a £100 million flyover to be built by 2021, but the MPs think the current funding gap is worrying and urge HE to do everything they can to ensure it stays on track.

A249 Detling Hill and M20 Junction 7

With vehicles likely to use this road to get between the crossing and Eurotunnel major improvements are needed.

M20 Junction 4

An extra 2,500 homes in Tonbridge and Malling borough will this already over capacity junction before the crossing is built. The MPs say southbound traffic must be directed away from the A228 once it leaves the crossing to avoid even greater pressure.

M2 Junction 7 (Brenley Corner)

The junction is now at capacity and has been identified as one of the country’s top 50 accident hot spots. Mrs Whately and co want to see this rebuilt urgently. Currently its set to happen by 2030 but the MPs say if it isn't done sooner the M2 will become gridlocked once the LTC is open.

A2 dualling

Widening the single carriageway sections of the A2 from Lydden to Dover is essential to complete the route to the port, they say.

M2

Measures like making the M2 into a smart motorway bring it up to three lanes need to be put in place before 2027.

M25

Junctions 2 (Darent interchange) and 3 (Swanley interchange) need investment.

Secure overnight lorry parking

They says the county has a severe shortage of lorry parking spaces. While 80 spots are planned as part of the LTC these, they argue, are not secure enough for drivers to take overnight breaks.

The letter concludes: "A free-flowing corridor to the ports is essential for the whole UK economy – so making the necessary upgrades to our roads to support the Crossing should be a national priority."