Leading article: The choice is obvious. Unfortunately

But, for all their understandable impatience to put the embarrassments of recent weeks behind them and rally behind a new leader, we hope that Liberal Democrats will not choose too hastily. It may seem as though this contest has been in progress forever and that delay will only be more destructive than the events that have preceded it, but this is a contest, and leadership, that matters. The candidates deserve their chance to present their case and the party members should take time to weigh what they hear.

In many ways, this contest - as it has played out so far - has been the very opposite of the competition to lead the Conservatives. The Tory contest brought out the best of the party. It vindicated the requirement to ballot the membership and it left the party sounding fresher and more confident than for many a year. Alas, any hopes the Liberal Democrats might have had that a leadership contest might do the same for them were shattered well before any voting had begun.

The manner of Charles Kennedy's enforced departure was scrappy, bringing together all the amateurishness for which the Liberal Democrats are known, and all the deviousness in politics that the party purported to eschew. The meltdown that followed, with the resignation of Mark Oaten and the convoluted clarifications by Simon Hughes, not only depleted the ranks of aspiring leaders, but precipitated a catastrophic fall in the party's poll ratings. Whoever becomes the next leader will have his work cut out to rebuild the party's credibility and win back the voters.

This is why this contest matters so much. The party needs a leader with authority, a leader who will command respect both among MPs and in the country. It needs a leader who will be capable of unifying the party after this period of disintegration, and a leader far-sighted enough to forge the sort of policies that will attract new voters at the next election.

On top of all this, it needs a leader with, if not charisma, then the ability to use the mass media to his advantage. The medium of today's politics is the press, radio and television; the modern politician must also be something of a performer to get his message across.

It scarcely needs to be said that none of the three candidates on the ballot paper meets all of these requirements. The dream of party members that they might acclaim their own Liberal Democrat David Cameron is not attainable. The most promising representatives of the younger generation - David Laws, Nick Clegg - have chosen to wait this contest out. And, in their own interests if not necessarily the party's, they are probably right.

The Liberal Democrats have a solid choice, but it is one that offers little real cheer or, indeed, inspiration. Regrettably, Simon Hughes' candidacy has been diminished. It is tempting now to ask how his prospects might have been different, had he been more frank about his personal life when he was asked directly about it. But direct questions deserve direct answers - or a categorical insistence that the private domain will remain private. To create a false impression that then had to be corrected reflects poorly on his judgement. In the next election - which will undoubtedly be at least in part about integrity - he would be fatally flawed as party leader.

One of the qualities that has distinguished the Liberal Democrats as a party was their reputation for integrity. It was a reputation they enhanced with their consistent opposition to the Iraq war and their doughty defence of civil liberties. It may be sad, but it is true, that in a party leader the personal cannot be separated from the political. Mr Hughes undoubtedly has a major role to play in the party in the future. He is one of the most energetic performers in politics at present and would have offered the most distinctive pitch in comparison with the two main parties, but he is now in no position to lead his party.

Chris Huhne is hampered by his lack of leadership experience and the brevity of his career in national politics. As David Cameron proved, neither is fatal if a politician has a gift for communication and personal charisma. Yet Mr Huhne, for all the solidity of his policies, lacks this essential ingredient for a party leader. He is to be commended for standing, and providing Liberal Democrats with a real choice. At this juncture, however, solidity is not enough. The leader of the country's third party needs to be capable of putting his party on the map.

This leaves the obvious candidate, the front-runner, Sir Menzies Campbell. Sir Menzies brings undoubted authority to the role. He has the overwhelming support of MPs and peers, and enjoys respect in the country. He is the one candidate who should be capable of uniting the party's left and right wings, and he has stated his intention of professionalising the party - a change that is urgently needed, as the shambolic exit of Charles Kennedy demonstrated. Sir Menzies' age need not be against him: experience could become an asset in competing for votes against a Tory party led by Mr Cameron, but it militates against his retaining the leadership beyond the next election. Contrary to the argument that Mr Huhne, among others, has made, this is not necessarily a disadvantage.

A doubt we have about Sir Menzies is whether, in recent months, ambition has somewhat impaired his judgement. During the initial phase of the crisis, he seemed content to promote his own candidacy, rather than acting as a unifying force and boosting the morale of demoralised activists. We are confident he will act in a more statesmanlike manner if he becomes leader.

In all, though, Sir Menzies is the best candidate. We wish the field were stronger. We wish he had more competition. But, as things stand, Sir Menzies is the only candidate with the authority to lead the Liberal Democrats at this difficult time. With the two main parties rapidly converging on the middle ground, British politics urgently needs a strong - and truly liberal - voice. If he is elected, we hope that Sir Menzies will rise to the challenge and provide that voice.