The country, the party, and even some of the candidates sense that the Labour leadership contest is a bit of a yawn. Downcast by defeat, the party is unsure how to respond. The hopefuls, who don’t brim over with hope, have chucked out manifesto ideas about taxing the rich, but not clearly explained how they would tackle inequality instead, or indeed any of the big challenges that will confront Britain in 2020. The air at the hustings hangs heavy with slogans that any opposition politician can mouth at any time: harness the power of community, break down old silos, don’t just treat the symptoms of social problems, dig down to the roots.

There are some good reasons for the state of confusion – such as the simultaneous need to woo back votes lost to Ukip, the Conservatives and the Scottish Nationalists, who all pull in different directions. Other causes of the disarray might have been avoided, like the party’s cart-before-horse scramble to find a new face before it has settled on what it thinks it stands for. Then there are the unnecessarily restrictive nomination rules, which mean that each candidate needs the backing of 35 MPs, in a shrunken parliamentary party, simply to get into the final ballot. As things stand, the only guaranteed choice is between Andy Burnham, Yvette Cooper and Liz Kendall. There are political differences between the three which should not be dismissed, but they are subtle. So subtle, in fact, that they might well go unnoticed by those who do not pay politics unusual attention.

One candidate, Mary Creagh, has already been squeezed off the ballot. Another, Jeremy Corbyn, is in danger of this fate. Neither deserves it. Ms Creagh’s politics may not be obviously different from those of her rivals: like Ms Kendall and Ms Cooper she complains of Ed Miliband’s disregard for business. But she is an assured media performer, less easy than some to dismiss as part of a political class. Why shouldn’t her party be able to consider whether she is its best shot at selling a moderate Labour message? Mr Corbyn is a very different proposition, a radical leftist whom few – and perhaps not even the modestly mannered Mr Corbyn himself – would imagine in No 10. But he too has a right to a place in a contest where his role could prove significant.

The welfare state is set for a sustained assault. That will pose thorny dilemmas for Labour, which could be entirely obscured in an exchange of empty cliches about “reform” if nobody does what Mr Corbyn will do, and vow to fight the cuts. His opposition to Trident could spark an overdue debate about defence, and his concern with civil liberties would be a useful corrective too. It would also be interesting to contrast Mr Burnham’s emphasis on the anxieties that many voters feel about immigration, with Mr Corbyn’s cosmopolitan, inner-London perspective.

In all these respects, having one name on the ballot who is fearless in defining himself could usefully force more definition on the rest of the pack. For the sake of the contest, some of the several dozen MPs who have not yet made a nomination should remember the fate of Mary Creagh and nominate Mr Corbyn.