Leading article: What is the point of a liberal who fails to stand up for individual liberties?

Sir Menzies Campbell was forced, somewhat contrary to expectations, to fight hard for the leadership of the Liberal Democrats. But the political honeymoon that might have followed his comfortable victory never came. Nor did the hoped-for gains in the local elections. Indeed, ever since he took over, the party's poll ratings have been on a downward trajectory.

Now, support for the Liberal Democrats is down to 16 per cent. Sir Menzies is having to defend himself against criticism from his own MPs. In the country at large, a bare 8 per cent - according to yougov.com - believe that, of all party leaders, he would make the best prime minister. No wonder he has decided that it is time to take a more assertive approach.

For yesterday's first in a planned series of high-profile speeches, Sir Menzies chose the subjects of the moment: our criminal justice system and law and order. The clear purpose was to counter the public perception of his party as "soft" on law and order. To that end, he called for new restrictions on foreign criminals who cannot, for whatever reason, be deported and for a new register of violent offenders. Rejecting outright a proposal by his predecessor, Charles Kennedy, before the last election, he said that those convicted of serious offences should not have the right to vote while in prison. And there was more in a similar vein.

It is always sad when an individual admired and noted for his strength of character trims his sails to the prevailing wind. But it was especially sad to hear Sir Menzies Campbell speak in such terms, given the personal stand he took against the Iraq war and the eloquence with which he subsequently presented his party's defence of civil rights against the illiberalism of the Government's anti-terrorism Bill. The consequences for the country are potentially even worse. If Sir Menzies continues down this path, we will lose the last source of real opposition to the hard-line Blairite consensus on law and order. If Sir Menzies and the Liberal Democrats are not prepared to speak up for personal liberty, we are compelled to ask who will.

In appearing to jump on the law and order bandwagon, Sir Menzies is drawing quite the wrong conclusions from his own and his party's current difficulties. So long as Charles Kennedy was leader and Sir Menzies was spokesman on foreign affairs, the party's appeal was only enhanced by its lone opposition to the Iraq war and its defence of individual liberties. The party achieved its best showing ever in last year's general election. At a time when so many voices are calling for a clampdown - whether on foreign offenders, early releases or lax parole - it is all the more important that a distinctive Liberal Democrat voice is heard.

Unfortunately for Sir Menzies, the party's immediate problem stems less from its policies - which are still under review - but from his own invisibility and the lacklustre performances he has produced in Parliament. He may resent the Prime Minister's Questions syndrome, whereby a politician is judged by his ability to score points in an often raucous debate but, as a veteran parliamentarian, he knew what he was getting into. And in the past, he has held his own.

There is no intrinsic reason why this "quiet man" should not score points in these debates. Nor yet on the media circuit, which is every bit as important for a modern British politician. But he will have to sharpen his focus. It is not only his confidence that Sir Menzies must rediscover if he is to become a convincing leader, but - most crucially - his own, and his party's, authenticity. The whole point of the Liberal Democrats is to be liberal and democratic: otherwise what is this party for?