An MP has claimed that queues to Dover could stretch back a staggering 180km after Brexit if new technology being used for border checks goes wrong.

Meg Hillier, the Labour chairman of the all-party public accounts select committee, made the claim as MPs quizzed the HMRC chief executive Jon Thompson about the potential impact of the new system, due to be introduced in January 2019, going wrong.

She said: “The queues [could be] 180km if there is a delay at the port of Dover. It could be catastrophic."

A 180km - or 112 mile - queue would potentially stretch from Dover back beyond London.

Shabana Mahmood, a fellow MP on the committee echoed the concerns, saying: “We would have queues at the ports of Dover, we would have rotting food.”

A new system for checks using up-graded technology is due to come into effect in January 2019 - two months before the Brexit date.

HMRC has said it needs an extra £7.3m investment to upgrade the system to prevent delays from 2019.

HMRC chief executive Jon Thompson told the public accounts committee back-up funding needed had yet to be confirmed but he was confident the system would be ready in January 2019.

He also said HMRC would need up to £450m in extra funding and 3,000-5,000 extra staff to deal with Brexit if the UK left the EU with no deal - the "most extreme version" of leaving.

The concerns are the latest to be voiced by MPs over the impact of Brexit on ports of entry to the UK.

Folkestone and Hythe MP Damian Collins warned this week that unless the government moved to build a huge lorry park off the M20 in time for Brexit, the county could face gridlock.

“Any time delays in processing freight in and out of the country will cause massive traffic disruption in Kent. We want the country to be ready for Brexit on Day One.”

“I believe that if there are customs delays, then Operation Stack will become a frequent and unwelcome visitor to the county causing massive disruption.”