Adults could be forced to prove their age to use social media along with teenagers if ministers go ahead with the 'strongest possible approach' to a ban for under-16s.
Under proposals to stop children using apps such as TikTok and Instagram, the Government said one option was to 'require every existing UK social media user to verify their age online'.
Its consultation published on Monday asked members of the public if they agree with the statement that 'adults should complete age checks more often, if it means children are safer online'.
If adopted it could make the UK's online safety regime more stringent than the one adopted in Australia earlier this year, under which firms can require facial scans to determine if users are 16 or older.
There have been reports that children have tricked the apps by simply screwing up their faces to look old.
The Department for Science, Innovation and Technology report admitted that current technology struggles to 'distinguish a 14 from a 16-year-old'.
Sources stressed that no decision has yet been made about how to proceed, with options short of a ban also on the table.
These include overnight curfews, restrictions on the addictive features of some apps or even just 'nudges' encouraging users to take a break.
The UK government is consulting on measures 'to prepare children for the future in an age of rapid technological change', which could include a social media ban for under-16s
Silkie Carlo, Director of civil liberties group Big Brother Watch, has warned that a social media ban for under-16s would mean mandatory ID checks for adults as well
But critics said that there was no reliable way to keep children off social media without requiring ID checks on adults too, by requiring all users to prove their age.
Silkie Carlo, Director of civil liberties group Big Brother Watch, told the Daily Mail: 'The only way to ban children from social media is through mandatory online ID checks for us all, adults and children alike.
'The government would have to choose between mandatory ID checks, biometric age guesstimates or AI behavioural surveillance to estimate internet users' ages.
'All of the online age verification options are highly invasive and the biometric and behavioural profiling options are highly inaccurate, meaning IDs will be required in many millions of cases regardless.'
She went on: 'Parliament should reject calls for a social media ban and focus on supporting parents and schools to help children use the internet in a positive and healthy way.'
However ministers are under pressure to take tough action from many MPs and impose a ban on under-16s using social media rather than just recommending overnight curfews.
Daniel Kebede, General Secretary of the National Education Union, said: 'Children are not just being harmed because they are online too late at night - they are being harmed because algorithms are designed to push them towards the most shocking, violent and sexual content from the moment they log on.'