Leading article: An opportunity for a bold leadership campaign

The candidates' list for the Labour leadership election has been confirmed. Now a long campaign looms, with the victor not due to be announced until 25 September. The protracted nature of the process is sensible. After the Conservatives lost heavily to Tony Blair's resurgent Labour in the 1997 election, the party's MPs hastily chose William Hague as their new leader. It proved to be a disastrous choice. By taking its time to select a new leader, Labour has clearly learned from the Tories' mistake 13 years ago.

But while a tight deadline will not be a problem, there is a rather disappointing lack of variety among the candidates who have made it through to the final stage of the contest. It is welcome that Diane Abbott secured enough nominations at the 11th hour yesterday to make it onto the final ballot, ensuring that this will not be an all-male affair. But the veteran Labour MP has herself admitted that her primary motivation for standing was to ensure a greater choice in the contest, rather than a burning desire to lead the party.

The background of the other candidates – Ed Balls, Ed Miliband, David Miliband and Andy Burnham – is depressingly similar. They are all Oxbridge-educated, former government researchers who were fast-tracked into safe seats through central patronage. They are career-long political insiders with no substantive experience outside the Westminster bubble. And none can be said to be a big political character either. To some extent this is not their fault. The upper ranks of the Parliamentary Labour Party have been stifled by the long Blair-Brown duopoly. No one else could really grow in the shade of those two giant trees. But the unfortunate result is that the five candidates – with the exception of the left-wing Ms Abbott – appear very ideologically close; all very much in the New Labour mould.

That said, there is evidently considerable talent and ability in the field. The task of the individual candidates over the next few months will be to demonstrate that they have a distinct and coherent vision for the Labour Party. They need to show that they have moved beyond the Blair-Brown era and its tired old slogans and instincts.

They need to articulate a progressive response to the inevitable era of fiscal austerity that Britain is entering. Simply promising to fight the cuts is not a credible platform. We need to know what government functions the candidates would drop, as well as defend. We need to know what taxes they would raise, rather than those they would just leave alone. And this all needs to be tied together by a clear philosophy of the state's role. On Britain's position in the wider world, the candidates need to show that they have learned the lessons of the disastrous invasion of Iraq which did so much to demoralise the Labour Party and alienate large sections of the country.

And it is essential that, in the weeks ahead, they speak to the wider population, not just their fellow MPs, party members and affiliated trade unions. To appeal only to the Labour Party's activist base would be to risk putting the party into perpetual opposition. This is an opportunity for the candidates, freed, as they will be, from the stifling constraints of office and the normal chains of internal party discipline to campaign boldly. They must seize it.

The country at large will not get to influence the outcome of this election. But we should take a close interest in the process nonetheless. It will be an advantage to David Cameron's coalition government that there will effectively be no opposition for the next three-and-a-half months. That cannot be helped. But after September a strong and competent opposition will be vital for our democracy. It is in all our interests that Labour chooses wisely.