The Government will later this month announce details of a controversial national identity scheme which will allow people to use their mobile phones and social media profiles as official identification documents for accessing public services.
People wishing to apply for services ranging from tax credits to passports will be asked to choose from a list of familiar online log-ins, including those they already use for social media sites, banks, and supermarkets, to prove their identity. Once they have logged in correctly, the site will send a message to the agency authenticating that user's identity.
The Cabinet Office is understood to have held discussions with the Post Office, banks, mobile phone companies and Facebook, Google, Microsoft, PayPal and BT.
Ministers are anxious the programme is not denounced as a "Big Brother" national ID card by the back door, which is why data will not be kept centrally by any government department. Indeed, it is hoped the Identity Assurance Programme will end any prospect of a physical national ID card being introduced in the UK.
The identification systems used by the private companies were subjected to security testing and awarded an "Identity Provider" kitemark, meaning that they have made the list of between five and 20 approved organisations that will be announced on 22 October.
The public will be able to use their log-ins from a set list of "trusted" private organisations to access Government services, which are being grouped together on a single website called Gov.uk.
The system will be trialled when the Department for Work and Pensions starts the roll-out of the Universal Credit scheme in April.
But privacy campaigners are not wholly convinced. "Although this is a fine scheme in principle and is backed by ministers, the danger is that it could be sidelined and used as a fig leaf by the data-hungry government departments," said Guy Herbert, general secretary of No2ID, which has been consulted by the Cabinet Office.