Leading article: Only a quick resolution of this crisis can save Brown

After Labour's dismal performance in the Crewe and Nantwich by-election and the bout of febrile speculation about the party leadership that has followed, New Labour is entering one of its most critical phases since it secured power in 1997. The stakes could hardly be higher; one way or another, the party now has to make the key moves and decisions that will last it until the next general election.

Obviously, the most pressing question is whether to stick with Gordon Brown as Prime Minister or choose a successor. This is has been the main issue since Crewe. But it is also a far more complex question than it seems. On the surface, it might appear clear that the party ought to ditch a leader who has clearly become very unpopular with the electorate if it is to have any chance of regaining the political initiative. But it is a strategy that reeks of desperation, and it carries risks. It would be a massive move for the party to make at a time when there is no clear alternative leader. Some names being bandied about, starting with David Miliband and James Purnell, may have the attributes of youth and freshness, but they have serious weaknesses; not least the fact that none has been tested in a political storm. Other names seem even more desperate, such as Jack Straw, the Justice Minister, a man forever tied to the misadventure of the Iraq War.

Whatever it decides to do in resolving this dilemma, the party must do it quickly. If not, the speculation concerning the leadership will continue, becoming ever more destabilising for the Government. Resolving the leadership question, therefore, is almost as important as the actual outcome. Either the party must stick with Gordon Brown, despite his obvious flaws for much of the electorate, or it must move quickly and decisively to create the circumstances in which a replacement can be installed.

Resolving the leadership crisis is not enough in itself. The Government and the Labour Party need to be clearer than they have been about their overall sense of purpose. It is all very well for MPs and cabinet ministers to list Gordon Brown's character deficiencies and policy mistakes in private, but so far few have offered a clear and coherent alternative agenda that stands much a chance of leading the Government out of the hole in which it now finds itself.

If Mr Brown is given the time to continue in office, then he, too, must bring a greater sense of purpose to his leadership. Merely talking about the long-term decisions that he is taking for the benefit of all of us, as the voters in Crewe recently reminded us, is not enough. He needs to show that he understands the concerns of the electorate, and that he has a genuine vision for these difficult times.

Finally, the conflicting voices within the Government might want to start focusing more attention on David Cameron and his high-flying Tories. If the Opposition has succeeded in becoming much more popular, albeit without much scrutiny of its policies or of what it stands for, that is partly the responsibility of its opponents. Labour seems too busy looking inwards to expose the limitations of the Tories, something underlined by the absurd and negative campaign fought in Crewe.

The next few weeks will be highly charged within the Labour Party. But it is important to remember that with up to two years to go before the next general election, defeat is not inevitable. Not yet. However, if the party fails quickly to clarify its position over the leadership and explain how it plans to meet the Tory challenge, it will indeed be doomed.