Andy Briggs recently wrote on this blog that “any Liberal government worth its salt would repeal the sugar tax”. Certainly, the justifications that the government has given are to do with deterrence, and I agree that those are illiberal – but there is a much more compelling reason to support the principle of this policy, and one which goes right to the core of liberalism.

It is undeniable that a diet of sugary foods leads to obesity, and undeniable that obesity is one of the great killers in this country. But not only that, it’s costly – according to Public Health England, the NHS spent over £6bn in 2014/5 on obesity-related illness.

The sugar tax is often mooted as a way to deter people from eating junk through higher prices, but this justification is a weak one, mostly because price increases are unlikely to put off people who are addicted or can’t get over their cravings. Liberalism is a philosophy with many subdivisions and competing inner schools of thought, but personally, I agree with John Rawls’ view that the state should not consciously promote any particular conception of what constitutes the good life. But there is another justification for the sugar tax which does not rely on such paternalistic reasoning, and it’s one which all liberals should support.

We should view the sugar tax as a way to ensure that those who choose to eat unhealthily contribute towards the cost of treating the obesity-related illness which arises through their choices. Liberals by their nature give priority to the rights and claims of the individual above other perfectionist or utilitarian considerations. And in this sense, if individuals choose to eat unhealthy foods, it is them who should pay for the unnecessary additional burden being placed on the NHS, rather than adding to the financial burden of those who eat healthily.

A typical rejoinder to this point of view is that it undermines the principle of universal healthcare, but I don’t believe it does. As a society, we are rightly in broad agreement that a universal, free-at-the-point-of-use NHS is the best way to deal with healthcare, and those who fall ill through rotten luck or unforeseen circumstance. But increasingly, we are faced with shortfalls in funding, not least due to the aforementioned additional burdens imposed by those who choose to smoke, excessively drink, or overeat, in full knowledge of the consequences. If we are to fund the NHS properly, the question has to be asked – who should pay for these unnecessary additional costs? Should it be everyone picking up the tab for the obviously unhealthy choices of others, which countless public health campaigns and basic schooling programmes have taught, or should it be the individuals themselves, paying a simple, small extra levy on the foods which contribute to the problems? I personally choose the latter. This in no way harms the idea that any person who falls ill should receive treatment – it just thinks realistically about how it should be paid for.

In this way, the state remains neutral on whether it’s a good thing or a bad thing to smoke), or drink, or overeat – if people choose to do so, that’s their choice, and they are free to make it. But they are not free, by that choice, to impose additional costs on the taxpayer, and make other people pick up the tab for their obviously, foreseeably poor decisions. Nor, as Andy Briggs claims, does this logically lead to taxing gym memberships. Exercising, in the normal foreseeable course of things, is an entirely healthy activity. It does not cost the NHS a significant amount of money to treat exercise-related injuries. By contrast, eating sugary foods is an entirely unhealthy activity, and costs the NHS more than £6bn every year. The two are clearly not comparable.

In sum, then, although the government justifies it wrongly in the present iteration of this policy, sugar taxes generally – just like tobacco and alcohol duties – can be reasoned for from a liberal point of view. In this non-perfectionist, liberal way, I think we should support the policy.

* Harry Samuels is a Lib Dem candidate at the local elections in Oxford and a final-year Classics student at the University of Oxford.

* Harry is Communications Officer for the Young Liberals. He lives in South London, where he is training to be a barrister.