ReutersThe government has announced plans to introduce a digital ID system across the UK, with Prime Minister Sir Keir Starmer saying it will ensure the country's "borders are more secure".
The IDs will not have to be carried day-to-day, but they will be compulsory for anyone wanting to work.
The government says the scheme will be rolled-out "by the end of the Parliament".
The digital IDs will be used to prove a person's right to live and work in the UK.
They will take the form of an app-based system, stored on smartphones in a similar way to the NHS App or digital bank cards.
Information on the holders' residency status, name, date of birth, nationality and a photo will be included.
Announcing the scheme, Sir Keir said: "You will not be able to work in the United Kingdom if you do not have digital ID. It's as simple as that."
The government says the scheme is designed to curb illegal immigration by making it harder for people without status to find jobs. Ministers argue this is one of the key pull factors for migrants entering the UK illegally.
Employers will no longer be able to rely on a National Insurance number - which is currently used as part of proof of right to work - or paper-based checks.
However, Conservative leader Kemi Badenoch said that while there are arguments "for and against" digital ID, making it mandatory "requires a proper national debate".
In a post on X she said: "Can we really trust [Labour] to implement an expensive national programme that will impact all of our lives and put additional burdens on law abiding people? I doubt it."
Liberal Democrats' Shadow Attorney General Ben Maguire told the BBC the party was "struggling" to see how the policy would have a meaningful impact on illegal migration.
Digital ID will be available to all UK citizens and legal residents, and mandatory in order to work.
However, for students, pensioners or others not seeking work, having a digital ID will be optional.
Officials also stress it will not function like a traditional identity card: people will not be required to carry it in public.
Ministers have ruled out requiring the ID for access to healthcare or welfare payments.
However, the system is being designed to integrate with some government services, to make applications simpler and reduce fraud.
The government said that, in time, digital IDs would make it easier to apply for services such as driving licences, childcare and welfare. It said it would also simplify access to tax records.
The government has promised the system will be "inclusive" and work for those without smartphones, passports or reliable internet access.
A public consultation expected to be launched later this year will include looking at alternatives - potentially including physical documents or face-to-face support - for groups such as older people or the homeless.
The UK government has said it will "take the best aspects" of digital ID systems used elsewhere around the world, including Estonia, Australia, Denmark and India.
Each of these countries has its own unique system, but all use it as a way for people to prove who they are when accessing certain government or banking services.
Many other countries also use digital ID of one kind or another, including Singapore, Greece, France, Bosnia and Herzegovina, the United Arab Emirates, China, Costa Rica, South Korea and Afghanistan.
Yes. Tony Blair's Labour government legislated for voluntary ID cards in the early 2000s.
However, the scheme was scrapped in 2011 by the Conservative-led coalition, which argued it was too costly and intrusive.
The UK has only had compulsory ID cards during wartime. Although they stayed in place for several years after World War Two, Winston Churchill's government scrapped them in 1952 following criticism over costs and police use.
Civil liberties groups argue that even a limited digital ID could pave the way for a more intrusive system, raising concerns about privacy, data security and government overreach.
Big Brother Watch, alongside seven other organisations, has written to the prime minister urging him to abandon the plan, saying it will "push unauthorised migrants further into the shadows".
More than 850,000 people have signed a petition against introducing digital ID cards, on the UK Parliament website. Petitions that get more than 100,000 signatures are considered for a debate in Parliament.
Other prominent critics include the former Conservative cabinet minister David Davis - who campaigned against Labour's ID card scheme in the 2000s.
He said "no system is immune to failure" and warned governments and tech companies have repeatedly failed to protect people's data.
