The next leader of the Labour party has probably been elected. The majority of people who are going to cast their votes have almost certainly done so. A few ballot papers remain on mantelpieces or shoved onto ‘to do’ piles. But if you’re going to vote the chances are you’ve done it.

It’s such a monumental decision, it’s humbling that a tiny slice of it belongs to me. I feel the same frisson when I go to a polling station. Our federal structure has led to much head-scratching from commentators. It means of course that many Labour party members have more than one vote. They can vote as party members, as members of affiliated trade union, and as a member of a socialist society. For people who like joining things (the kinds of people who signed up to every club and society at freshers’ fair) it is theoretically possible to have a dozen or more votes – as a member of one or more trade unions, the Fabian Society, the Christian Socialists, the Society of Labour Lawyers, and so on. This time round I managed only three votes (Fabians, Unite and the party); my record, I think was the six or seven I cast for John Smith.

All the evidence points to David Miliband as the winner (although I have a small stake at Ladbrokes on his brother). David will win because the party has listened to the arguments, and come to a view on what kind of party we should be. The big buzz is around second and third preferences. A mythology has developed that Ed Miliband will win on the transferred votes of people who voted for Ed Balls, Diane Abbott or Andy Burnham as their first preference. There is no evidence, either from academic studies of preferential voting systems, or from the telephone canvass returns from the various camps, that there is a strong pattern of voting for Ed Miliband in second place. The distribution of second place votes will probably mirror those of first place votes – which means that David Miliband will be ahead in the second round as well as the first, and might well cross the winning line early in the process. The ‘Ed wins on transfers’ is a myth.

David Miliband, elected on Saturday 25 September will have two days to prepare for his first leader’s speech amidst all the clamour for attention and demands on his time. It needs to be a speech which starts the long march back to government, unites the party, provides an alternative vision to the Tories’, and starts to connect with the public. He could do worse than to cajole Phil Collins to help, the man described by Tony Blair in The Journey as ‘by far the best speechwriter I ever had’. It needs to exude emotional intelligence, and demonstrate empathy with the hard-working majority who feel ever-more under the cosh. It needs to set out the definitive position on the deficit. It must pick the right fights with the government, but avoid oppositionalism. It should tell the party some tough home truths about the road ahead. It needs a few great gags and the odd memorable line. I hope someone has started work on it already.

On 7 October, he will see the people elected by the parliamentary Labour party (PLP) to form his shadow cabinet, and allocate portfolios, including the all-important post of shadow chancellor. Miliband will have to shuffle the hand he is given. He will have to deal intelligently with the candidates he has defeated. He will need to bring on the new entrants to the shadow cabinet, including the surprise victors that no-one predicted. He should create a balanced shadow cabinet, from across the political wings of the party, and from different parliamentary intakes. We must hope that the PLP has the collective wisdom to choose the right combination of intellect, tenacity and guile to cause the Tories and Lib Dems the maximum amount of trouble.

Then, on 20 October, under a month since his election, he will lead the Labour party’s response to the government’s comprehensive spending review (CSR), when the full menu of cuts will be revealed. This gives Labour the ultimate platform to set out a different course of action on the economy – realistic, responsible, fair and in the national interest. A strategy for jobs and growth is the best answer to the issue of deficit reduction. When George Osborne promised a further £4 billion in cuts to the welfare bill last night, it was because he knew his policies are poised to send unemployment into orbit. Osborne wants to weather the self-inflicted rise in unemployment on the cheap. But Labour needs a convincing story to tell too on how, when and why it would reduce public spending. The ‘deficit denier’ charge has currency unless we can show how we would cut out bureaucratic waste and duplication. There’s nothing inherently progressive about high levels of tax and spend.

By the weekend of 23 and 24 October, the shape of economics and politics for the rest of the parliament will be clearer, and the five million voters that Labour lost since 1997 will have their chance to judge us afresh. It’s not just a test for David Miliband, and the smart people around him. It’s a test of the whole Labour family, and how serious we are about a return to government.