Anybody who objects to their personal details going on the new "Big Brother" ID cards database will be banned from having a passport.
James Hall, the official in charge of the supposedly-voluntary scheme, said the Government would allow people to opt out - but in return they must "forgo the ability" to have a travel document.
With one in every eight people saying they will refuse to sign-up, up to five million adults could effectively be refused permission to leave the country.