Britain’s trade and tourism could be undermined because of the bungled implementation of passport checks, a report has warned.

Its government has pledged to introduce 100 per cent exit checks on passengers leaving the UK by early next month.

But MPs have warned the policy “could introduce delays and queues, that these will be highly visible and could have a serious impact on UK business, trade and tourism”.

The changes are due to come into force on April 8, just after the Easter weekend.

The government has admitted it has restricted the scope policy and not everyone will be checked: a development the committee branded “concerning”.

Port queues are going to stretch to Folkestone

The report, entitled The Work of the Immigration Directorates Calais, said: “It is becoming obvious that the Home Office cannot guarantee exit checks will be in place on April 8, 2015.

“Logistical problems remain around how to inspect passports for 50 individuals in a coach, who cannot be seen from the check-in booth. This has been known from the start.”

The MPs said they “would not be surprised if further forms of travel or categories of passenger were declared out-of-scope to allow for exit checks to be declared a success”.

And they demanded a definitive list of which people who would not be subject to the checks.

A Home Office spokesman said: “We are very clear that we will be meeting our commitment on exit checks.

“We have been talking in particular to the ports and maritime and rail operators involved in this since 2013 and we have had considerable discussions and collaborative work with them over the best way to bring in these checks ensuring the least disruption possible.”

He said contingency arrangements have been drawn up if ministers run into problems with implementation.

“It will improve our ability to identify which people have overstayed, take targeted action against those abusing the law and identify and tighten the immigration routes and visas that are most vulnerable to abuse,” he added.

“Exit checks will also improve security by helping the police and security services track the movements of known criminals and terrorists.”

Keith Vaz, chairman of the Home Affairs Committee, said the date for the checks has been pushed back and MPs urgently “need to know what the exemptions are”.

He said that ferry operators have warned the new checks will lead to snaking queues at ports.

The Labour MP said: “The time it will take to check a single car will increase from 45 seconds to 80 seconds.

“That might not sound like a lot for individual cars, but if you tot it up on the thousands of cars that go on the ferries that is a huge number.

“The queues are going to go back all the way to Folkestone.”