All newly qualified drivers will be required to decide whether to donate their organs in the event of their death in a controversial move to boost the number of transplants. The plan, due to take effect in July, is the latest initiative to emerge from the government's 'nudge unit', formally known as the Behavioural Insight Team, which aims to change people's behaviour without resorting to legislation.

I still remain doubtful about this initiative. True, if you ask people whether they would like to donate their organs, about 70% say yes. But only a tiny fraction actually do anything about it. By giving people the choice at key stages in their lives – when they get a driving licence, for example – many more will tick the box. And that has to be good, hasn't it?

Well yes, provided the choice that people are given is benign, and remains a genuine choice. No sooner was the 'nudge' philosophy circulating than various advisers to the last government were proposing that smokers should be required to fill out a 28-page form before buying a packet of gaspers, and other such nonsense. That's a case of people still having some choice – but the choice being skewed beyond reason and endurance. I am hardly free if my preferred choices are made hugely inconvenient, or if I am subjected to public humiliation and personal abuse for making them. Drinkers and fatty-food lovers be aware.

But then, how far should politicians deign to 'nudge' us into the 'right' actions – including actions that we say we would like to take, even if in the event we can't actually be bothered? One can see the general public benefits of people being nudged into donating their organs, so there is some case for that. There is a lot less general public benefit in nudging people into people smoking, drinking and eating less, or popping fewer illicit pills and taking more exercise, for that matter. These are things that affect mostly the individual, not the public.Nevertheless, politicians feel they have a right, even a duty, to bring about a change in these and other parts of our lifestyle, just because they think it would be 'better' for us. Maybe it would, but if our sloth and gluttony don't affect anyone else, what business is it of the government to stop us, or even nudge us?

And where does the interference based on 'behavioural insight' actually end? I can foresee some future government that thinks capitalism is undesirable trying to nudge us out of it by ritually humiliating a few entrepreneurs. Indeed, when I look at the attitudes and actions of Business Secretary Vince Cable, I think this might already have started to happen.