Operation Stack could be solved - but with a possible price tag of at least £468m, we can reveal.

That is according to a working group set up to come up with alternative options to the scheme after the county ground to a halt this summer amid 32 days of gridlock.

And even if the package of measures were fully implemented, it could still mean as many as 1,500 HGVs having to be parked on the M20 and a lorry holding area off the M20 motorway for some 4,000 lorries.

The plans have been put forward by a group which consists of Kent County Council, Highways England, Kent Police and others.

The government directed the group to come up with ideas for more permanent solutions to Operation Stack.

The masterplan includes:

• Strengthening the hard shoulder of the M20 between junctions 10 to 8
• Improvements to the A20 in and around Dover to increase capacity and remove bottlenecks
• Improving the use of communication technology
• Potential lorry park close to the M20 to hold up to 4,000 HGVs
• An extension of the STOP24 lorry park at Folkestone for up to 1,000 more lorries

If all the measures were implemented, together they would cater for as many as 6,500 HGVs - but of those, 1,500 would still be parked on the motorway.

Cllr Matthew Balfour, KCC’s cabinet member for transport, said the costs could be justified given the widespread disruption caused to the country over the summer.

“I do believe there is a good case and not just because of the costs to the haulage industry, which they have put at £250m a day.

"More to the point is the disruption to the people of Kent, caused by not being able to go to the shops, being able to run their businesses and missing hospital appointments.”

He said that it would be for Highways England to decide what to do and more work needed to be done on the possible costs to the public purse.

“What I don’t want to happen is for the Treasury to turn around and say: ‘This is not worth it.’

"Unless we can justify that in real terms, the cost benefit analysis will fit with the Treasury’s demands, the next time it happens, Kent will grind to a halt again, with all the misery and disruption to the people of Kent and indeed the wider economy. I just don’t think that is fair.”

A report to be discussed by county councillors next week states:

“The preliminary cost for this package is £468m.

"The key issues around implementation concern certainty of funding, who will deliver and timescales for delivery.

"While some measures could be delivered in the short term, for others the timescales could be over the next two-to-three years.”

It says detailed plans will be needed to take some of the proposals through the planning process.