In the lead-up to Monday’s announcement of the rules and timetable of Labour’s leadership contest, there were fears that this vital process of renewal could descend into acrimony before it had properly begun. Time is certainly tight for candidates to gain the requisite number of MP and MEP nominations, and for new supporters to register to vote. But by sticking to the format of the last leadership election in 2016, the party’s national executive committee has largely avoided allegations of a race rigged to favour a Jeremy Corbyn-friendly successor.

That is one obstacle cleared in the hugely daunting journey towards to restoring credibility to a battered political institution. As Labour picks itself up, dusts itself down and decides who will replace Mr Corbyn at its helm in the spring, it must at all costs avoid succumbing to sectarian temptations. After winning fewer seats than at any election since 1935, and losing so many of its northern strongholds, the party needs all the political talent and all the fresh thinking it can muster. It must become a broad church again, and Labour’s ability to conduct this contest in an appropriately ecumenical spirit will be one of the key indicators of its future viability.

At the outset of the race, the prospects of that seem better than might have been expected in the wake of Labour’s recent polarisations. The dire nature of Labour’s predicament has been well rehearsed in the weeks following Boris Johnson’s triumph on 12 December. If the long haul back is to be successful, it is possible to be hopeful that the leadership candidates so far declared, or presumed to be standing, each have something important to offer towards the party’s rehabilitation, whether or not they win the prize.

As Boris Johnson attempts to turn his Brexit slogan into a reality that does not compromise the country’s economic interests, Sir Keir Starmer carries the authority and aptitude for detail that can expose the prime minister’s bluff opportunism and lack of a plan. Sir Keir’s warning that Labour should not rush rightwards in response to defeat was also well judged. On one level, this is clearly a calculated pitch to the party’s left-leaning membership. But he is right to maintain that the Corbyn era’s emphasis on radical renewal of the public sphere remains a necessary part of any Labour recovery.

Rebecca Long-Bailey has already been cast as a “continuity candidate”, in an election where change is imperative. But her suggestion that Labour needs to rediscover a way to articulate a “progressive patriotism” identifies one of the areas in which the party fell short under the leadership of Jeremy Corbyn. Lisa Nandy’s work on the cities/towns divide has highlighted another critical dimension of the party’s defeat, and her critique of Labour’s Londoncentrism is both valid and necessary. Jess Phillips and Clive Lewis are both charismatic performers, a quality that will be vital in a parliament whose rhythms and style will be dictated by the showmanship of Boris Johnson. The shadow foreign secretary, Emily Thornberry, has the capacity to move Labour away from the cold war-style leftwing internationalism that alienated much of Labour’s working-class base from Mr Corbyn.

Labour’s defeat was momentous in its scale and scope, and its causes were multiple. The debate between now and 4 April, when the new leader will be elected, needs to be constructive, honest and adequate to the size of the task. There is no quick fix, whoever becomes the next leader, and there will be unexpected twists and turns in the road ahead. But the varied insights and expertise of an impressive roster of candidates is a good platform on which to start. Harnessing those abilities in an open and non-confrontational debate, involving the whole party, is now imperative for Labour. In a crisis of this magnitude, the process must be right for the outcome to be worthwhile.