I'm sure the government will be keen to step in and provide this "service". I'd have thought WoT would be the solution, but as pointed out, it's only as strong as the "trust" assertion. IIRC PGP recommended "you only sign in someone's physical presence". I wonder if a solution might be similar to that, but with "accrual of evidence". I.E: we don't trust just your gas bill, these people were asking for a number of items to cross an internal threshold. It might be "these people say you are edent. And your id is signed with your website EV certificate. And the energy company asserts they have had transactions with you. And the bank says. And government gateway says. Etc".