Calais migrant crisis: The cost of Operation Stack to the UK economyIBTimes UK

The government needs to convince MPs that a proposed biggest-ever lorry park in Kent would be the best alternative for Operation Stack. The Department for Transport (DfT) is soon to decide on a new parking facility for lorries and stop vehicles using stretches of the M20 during periods of high capacity on cross-Channel services.

Stanford Lorry Park – a £250m parking site roughly the same size of Disneyland in California – has been proposed just off the motorway near junction 11, but plans have been dealt a setback by the Transport Select Committee.

MPs say not enough has been done to convince them the idea is the best one and the decision to push ahead with the 4,000-space site was made in "haste". Critics argue the new lorry park would destroy 150 acres of countryside to make way for a "concrete monster", but Labour MP Louise Ellman, chair of the committee, said a solution must be found.

"It is vital a solution that a solution is found but we have not seen a proper assessment of perhaps a series of smaller lorry parks, an upgrade of the road network, moving more freight onto rail. None of these things have been looked at in depth," she told the BBC.

"The disruption caused by Operation Stack affects many people in Kent but this is not just a local issue. The routes to Dover and Folkestone are important nationally – they carry more than 80% of the road freight entering or leaving the UK.

"The Government has settled on a lorry park as the best solution but what they are proposing is on a vast scale and could cost up to a quarter of a billion pounds.

"Ministers need to do more in order to justify this spending and it should do more to demonstrate why a lorry park roughly the size of Disneyland in California is better than the alternatives we heard about during our inquiry.

"We are not saying that the Government should not press ahead with its proposal, only that it has more work to do to persuade us of the business case for this investment."

Labour MP Louise Ellman

Operation Stack comes into action during high volumes of freight or incidents at the Channel Tunnel or the Port of Dover. It sees lorries park along the M20 in Kent and has been deployed when bad weather, strikes and, as seen last year, during incidents involving migrants in Calais.