A citizen’s income would require two big principles to be accepted and supported by the public, namely that:

Everyone should get a baseline level of state financial support, even if they choose not to do anything to try to earn money for themselves. The basic marginal tax rate should be much higher than it is now, otherwise almost everybody’s net income from the state would rise, and there is no obvious way to finance this. (Some do not assume UBI must be paid for through income tax and suggest a wealth / carbon tax instead, or bigger cuts to state spending elsewhere, for example. None of these are easy options either).

Most politicians in the UK (or in England at least) are likely to regard both of the above as unacceptable to voters - a view supported by long-standing evidence on public attitudes to welfare.

A third objection relates to support for housing (and other) costs. For UBI to achieve its goal of removing the complexity and disincentives involved in means-testing, it would also need to replace support for housing costs. But with largely market-based rents, it would not be easy to include a simple rent element in a UBI payment without creating shortfalls for some or large surpluses for others. The same applies to means-tested childcare support. This counter-argument is strong – arguably public attitudes towards benefits and taxation could change but differing needs will not.

So, a central problem is that advocates of UBI either unconsciously or wilfully fail to acknowledge that the current system is designed to provide specific payments for people in specific circumstances (e.g. caring, disability, high housing costs, high childcare costs). If you sweep all of that away, you either have to level up, giving a massive boost to people without those specific needs (at huge cost), or you create a fall in income for those with them. Neither is remotely acceptable in any real world.