Caroline Nokes told the Commons Home Affairs Committee firms could find it ‘almost impossible’ to differentiate between new and long-stay EU migrants.
British tourists could face delays at European airports after Brexit, the Immigration Minister has admitted.
Caroline Nokes said the prospect of UK travellers ending up in “rest of the world” queues is “not unrealistic”.
In a wide-ranging session with the Commons Home Affairs Committee, she also acknowledged that in some cases it could be “almost impossible” for businesses to differentiate between EU migrants who have lived in the UK for years and those who arrive after Brexit.
Ms Nokes told MPs the priorities in the event of a no-deal scenario are security, the flow of goods and people, and revenue processes.
“Of course it’s feasible that there could be delays for people travelling through EU airports.
“The prospect of them ending up in rest of the world queues at some major airports across the continent is not unrealistic.”
Ms Nokes also acknowledged employers may struggle to establish whether a prospective EU worker is a long-term resident if they have not yet obtained the status that confirms their right to live and work in the UK.
She said the issue presents a “conundrum” but denied the future system is “unworkable”.
Under the Government’s proposed settlement scheme, EU migrants who have been in the UK for five years by the end of 2020 can apply for “settled status”, meaning they are free to go on living and working in the UK indefinitely.
Those who have arrived by December 31 2020 but do not have five years’ residence can seek to stay until they have, at which point they can seek settled status.
EU citizens who arrive in the implementation period, which starts after the official exit date in March, will face no new curbs on living and working in the UK but will be required to register if they intend to stay for longer than three months.
It will be almost impossible for an employer to differentiate between them and somebody who is a new arrivalCaroline Nokes
Ms Nokes came under pressure from committee members to explain how the system would affect businesses employing workers from the bloc.
She said: “You are absolutely right to point out that somebody who has been here for ten years and has simply not yet been through the scheme, it will be almost impossible for an employer to differentiate between them and somebody who is a new arrival.”
Ms Nokes said the approach would be “pragmatic” and the early enforcement regime would not be “overly rigorous”.
She added: “We are quite clear that this is absolutely one of the conundrums employers will face – that there will be people who have rights under the settled status scheme but haven’t yet gone through the process to evidence that.”
The settlement scheme is currently being trialled and will be fully operational next year.
It is anticipated the total number of applications could run to more than 3.5 million.
Ms Nokes told the committee: “It is going to be an enormous challenge for both employers and EU citizens who do have the right to work to make sure we get them through the scheme as efficiently as we possibly can.”
Her evidence sparked claims the Government’s approach to Brexit risks a repeat of the Windrush scandal.
Liberal Democrat Home Affairs spokesman Sir Ed Davey said: “Millions of EU citizens in the UK have been living under a cloud of uncertainty for more than two years.
“Far from clearing up that uncertainty today, the Immigration Minister made it worse.”
The Home Office said employers already need to carry out right to work checks on EU citizens, and that will not change.
A spokeswoman for the department said: “We will protect EU citizens’ rights when we leave the EU, in both a deal or no deal scenario.
“We are considering a number of options for the unlikely event that we reach March 2019 without a deal, and will set out more information shortly.”