WHICH is more dangerous to your health: driving a car, joining the Army, getting married, taking an active interest in politics, or buying cigarettes?

You can at the moment do them all before the age of 18. But this weekend it was revealed that the Government is planning to raise the age at which one may legally buy cigarettes from 16 to 18.

Such arbitrary age limits are riddled with inconsistencies. If you are old enough to make split-second life and death decisions at the wheel of a car, surely you are old enough to decide to walk to your nearest shop and buy some cigarettes.

As if age limits of this kind work anyway. It is quite common to see gangs of young teenage kids roaming around on bicycles flicking ash as they show off to their peers. If they can get their hands on cigarettes when they are 11 or 12 - either through stealing them from parents or persuading an older relative to buy them on their behalf - how will raising the age limit from 16 to 18 make any difference?

This does not mean to say that it is wrong to raise the age limit. Anything that provides even a little discouragement for people to smoke is welcome.

This just means to point out that the Government's policy on smoking is as hazy as a public bar full of tabbers.

The Government has decided that it is only bad for bar workers whose pubs serve food to inhale second-hand smoke. How can that be? Don't bar workers who serve only drinks deserve the same protection from the same danger?

The cynical are saying that raising the age limit is just a smokescreen to obscure the inconsistent nature of the proposed smoking ban - a proposal that does not fulfil Labour's manifesto pledge, and that will be tested by Labour backbenchers this week.

This argument suggests that the Government's spin doctors are capable of thinking so tactically. However, the idea could just be another ill-thought-out attempt - like last month's ban on alcohol on trains - to grab the headlines on a quiet weekend from a Government that is increasingly desperate to inject some momentum into its domestic agenda.