The Chamber is no place for the callow

Chloe Smith, 27, is too young, says soon-to-be 27 Matthew Bell

Of all the records to hold, I used to think the most impressive belonged to William Pitt the Younger, the youngest person ever to become prime minister, at the age of 24. It struck me that if you're going to be competitive about things, being the youngest person ever to achieve the highest office in the land was the one to go for. No one has come close since 1783. But you don't have to be competitive to find those who achieve greatness in their youth fascinating – listen to Mendelssohn's Octet and it's hard to imagine a 16-year old knocking off something comparable today.

Yet the election of Chloe Smith last week as Britain's youngest Member of Parliament, at the age of 27, fills me with a vague horror. Like Pitt, she has achieved high office well before her time, and there's no denying it's quite an achievement to see off 11 other candidates, even if you do have the full arsenal of the Tories' campaign kit at your disposal. No doubt Ms Smith is a perfectly bright and talented young politician, but as Carol Sarler illustrates above, looks tend to get the better of proven ability and experience.

It's a regrettable if inevitable truth that Chloe Smith's generation of middle-class twentysomethings is defined by vaulting ambition – either you have it or you don't. Those who don't generally have a much better time, taking endless gap years, dabbling in drugs and perhaps doing the odd desultory postgrad degree. Those who have it are busy vying for work experience placements, landing graduate training schemes, elbowing each other out of the way in a frenzied struggle to get ahead. Anyone who has a job in their 20s, even if they pretend not to, always has one eye on their career. The dreadful "what do you do?" question is never more loaded than when asked between members of this generation.

In professions such as sport and music, impatience of this kind is not only understandable but necessary, with the time bomb of physical fitness hanging over you. But what are the benefits of being 27 in politics? The greatest attribute any politician can have is good judgement, which must come only with experience. Ms Smith's campaign team argues she has plenty of first-hand experience, having been on secondment to Central Office and having worked for a number of MPs, including James Clappison, Bernard Jenkin and Gillian Shephard. But how much time has she had to make mistakes, surely the most useful way of gaining experience?

If nothing else, Ms Smith and her team don't seem to have been paying attention to recent Tory history. In politics, more than any profession, the danger of burning out too soon is great. How many times does one hear Tory thinkers lament William Hague's premature ascent to power, ruing the baseball cap and the 13 pints which will always be remembered disproportionately to his otherwise quite good record. It's widely accepted the damage is too great for him ever to make another bid for the top job, and yet he is only 48 – he's got nearly two more decades in politics ahead of him. Then there is Theresa Villiers, the shadow cabinet minister for transport, with whom parallels were yesterday being drawn by one Westminster insider: "Theresa was promoted very quickly and, as it turned out, over-promoted. She wasn't quite up to it in her parliamentary career."

The only way to go from the top is, of course, down. Now that we are all living much longer and won't have to retire until we are 70, it leaves 50 years in which to achieve greatness. What's the hurry? Next month I'll turn 27, and the thought of representing a constituency of post-expenses, recession-hit taxpayers is appalling. Anyone of my age who genuinely thinks they are ready to take on one of the most important offices in public life either has a deluded sense of their own ability or a worrying lack of self-doubt. But at least they'll have plenty in common with their fellow MPs.