EU citizens applying to settle permanently in the UK after Brexit may face delays due to the coronavirus outbreak.
The Home Office says it is facing a “challenging time” and new applications will take “longer than usual”.
More than three million EU citizens have been granted permission to live and work in the UK since the scheme opened last March.
An estimated 600,000 are yet to register before June 2021 deadline.
In a blog post, the Home Office said telephone calls will not be answered, and it had suspended receiving paperwork from applicants by post.
Centres where identity documents can be scanned have been temporarily closed, the department added.
The Home Office said the decision to scale back services had been made following government advice for people to work from home where possible.
However it added it would keep the situation under “constant review” and would try to reinstate services “in line with public health guidance”.
In addition, it said people would still be able to apply online and use the government-approved app to authenticate their identity documents.
Advice for applicants will continue to be available online, whilst they will be able to get replies via email with a “call back function when required”.
The department added: “where a person eligible for leave under the EU settlement scheme has reasonable grounds for missing the application deadline, they will be given a further opportunity to apply.”
EU and European Economic Area (EEA) citizens will have to apply to stay permanently in the UK, after the country left the bloc in January.
The June 2021 deadline to make an application is six months after the UK is currently due to leave a post-Brexit transition period this December.