Ahead of his likely election as Labour leader on Saturday, Jeremy Corbyn has been meeting with MPs to discuss which posts they could hold in his shadow cabinet. There is no more important position to fill than that of shadow chancellor. It is the leader and their chief economic spokesperson who function (or dysfunction) as a pair: Blair and Brown, Cameron and Osborne, Miliband and Balls.

John McDonnell, Corbyn's greatest parliamentary ally and campaign manager, has long been the favourite for the job. But some in the party are advising Corbyn that the appointment of the Socialist Campaign Group chair would undermine his promise to build a broad-based team and avoid factionalism. It would also mean an all-male team at the top, with Tom Watson regarded as near-certain to become deputy leader.

Two alternative candidates being discussed among MPs are shadow leader of the House Angela Eagle and shadow Welsh secretary Owen Smith, two figures from the soft left of the party.Eagle served for two years as exchequer secretary to the Treasury in the Brown government and was shadow chief secretary to the Treasury under Ed Miliband. Smith nominated Andy Burnham but, unlike many of his colleagues, has avoided attacks on Corbyn during the campaign. Asked whether he would serve under the left-winger, he said: “I have no difficulties about working with whoever is elected leader. My view is quite clear. Whoever wins the leadership deserves the support of the party in opposing the Tories and campaigning for a Labour victory in 2020.”

The current shadow chancellor Chris Leslie has ruled out joining Corbyn's shadow cabinet and Yvette Cooper, another would-be contender, has also said she will move to the backbenches.