On June 30, the deadline for the European Union Citizens Registration Scheme [EU Settlement Scheme, EUSS], 6,015,400 applications had been received but only 5,446,300 were completed, leaving 569,100 unprocessed.

As the deadline approached, the number of applications skyrocketed, reaching 12,000 per day. On the last day, according to the Daily Telegraph, 50,000 registrations were reportedly received.

The opposition Liberal Democrat party is criticising the Government for not extending the deadline, leaving more than half a million people not knowing what the outcome will be, one that could affect their rights to live and work in the UK.

The backlog in processing applications grew by 70 percent in June, when more than 400,000 people signing up to EUSS, but the Home Office was only able to complete 175,000 cases.

"Such anxiety and uncertainty is cruel and unnecessary," Liberal Democrat MP Alistair Carmichael said.

The EUSS was opened in 2019 following the UK's exit from the European Union to grant residence status to citizens of EU countries, Iceland, Switzerland, Norway and Liechtenstein and their close family members.

Permanent status ('settled status') is granted after five years of continuous residence in the country, but those who have been there for less time are given provisional status ('pre-settled status') until the necessary time has elapsed.

Without proof of status, or a certificate of application, people lose residence and work rights and access to health, education and social support services in the UK.

The Home Office has promised a "pragmatic and flexible approach" and to accept applications after 30 June, assessing situations on a case-by-case basis where there are reasonable grounds for delay.

By the end of March, the British government had received 376,440 applications from Portuguese nationals and 359,070 were completed, of which 203,310 were granted permanent residence status and 143,080 provisional residence status.

Independent organisations have repeatedly warned of the risk of tens of thousands of vulnerable people, such as minors in the care of social services, those with health problems, the homeless, victims of domestic violence, or the elderly, becoming undocumented.