EU nationals hoping to secure their futures in the UK post-Brexit could have a wait of up to 50 years, Angus Robertson warned the Prime Minister yesterday.

The SNP’s Westminster leader said staff cuts at the Home Office would create “totally and utterly unacceptable” delays in processing residency applications for the 3.2 million European citizens currently living in the UK.

Speaking during Prime Minister’s Questions, Robertson highlighted a cross-party parliamentary Brexit committee report which recommended the UK must guarantee the status of EU nationals living in UK and act unilaterally if necessary.

The report also highlighted that: “The current process for consideration of permanent residency applications is not fit for purpose and, in the absence of any concrete resolution to relieve the anxiety felt by the estimated three million EU citizens resident in the UK, it is untenable to continue with the system as it stands.’”

Referring to the report, Robertson pressed the Prime Minister.

He said: “Since 2010 the Home Office has seen its full-time equivalent staff cut by 10 per cent, so at current rates of processing applications for permanent residency, it would take the Home Office more than 50 years to deal with 3.2 million European nationals in the UK. This is clearly totally and utterly unacceptable.

“So will the Prime Minister tell us how quickly she hopes to be able to guarantee all European nationals permanent residence?”

Theresa May denied Robertson’s suggestions, adding the department is “more efficient” and most people will be dealt with online.

Ministers have come under increasing pressure to guarantee the post-Brexit residency rights of EU nationals, although they insist any agreement must secure the futures of more than one million Britons living in EU member states.

May replied: “You can’t just stand up and say, because actually the Home Office is getting more efficient, it’s going to be longer for answers to be given.

“Yes, the Home Office is getting more efficient at how it’s dealing with these things.

“I don’t know if you’ve ever heard about technology, but these days people apply online and they’re dealt with online.”

Peers voted to amend the European Union (Notification of Withdrawal) Bill, which gives May the power to start the formal process of leaving the EU, to guarantee the rights of EU nationals living in the UK. The Government will seek to overturn this amendment in the Commons next week.

Following the EU referendum on June 23, the First Minister told EU nationals they were welcome in Scotland and she held a meeting with hundreds of concerned citizens weeks after the vote, telling them “you are human beings, not bargaining chips” after they described their fears over their futures.

Around 173,000 EU nationals live in Scotland many of whom play a key role in the NHS as well as delivering social care. They were not allowed to vote in the EU referendum despite its impact on their futures.