The Challenge: in some ways tonight’s will be the most difficult of all the debates

Tonight is the so-called “Challenger’s debate”. Once again it’s an odd sort of debate, given that the only Challenger on stage with a realistic chance of getting into Downing Street will be Ed Miliband. His role tonight will have to be a fine balancing act between looking like the next Prime Minister – something he has surprised even his fiercest critics by doing well so far throughout the short campaign – and also not being pigeon-holed as the voice of “Westminster as usual”.

To do this Ed must be polite and courteous to most of his opponents but not obsequious. There must be no I agree with Nicola, Natalie or – God Forbid – Nigel. In fact it must be Ed’s role to lead the charge against Farage if he goes as outrageously off piste as he did with his disgraceful remarks on HIV at the last debate. Ed can and should challenge all the other debaters. But he must do it not as if he were talking over the despatch box, but over a cup of coffee.

This format has the capacity to play to many of Ed Miliband’s strengths. He is a  thoughtful and consensual person. Tonight perhaps we could see how politics might really look without the Punch and Judy. Ed must call on the passion he has so far demonstrated so well as to why he wants to lead the country and channel that into persuading potential switchers looking for an end to austerity that he is on their side. That he understands the frustrations that brings voters to vote for the challenger parties but that he is their only realistic chance for change.

With David Cameron and Nick Clegg running scared of the challenge, Ed will be painted by every other leader on that stage as the voice of Westminster. He will need to take that up and make sure his is the voice that will change Westminster. He will be the only one with the power to actually do so and it is something he is genuinely passionate about. Let that shine through tonight not in his frustration with the petty needling from his stage mates, but in clear answers for the audience.

Ed should note the absence of David Cameron and Nick Clegg for the insult to the voters that it surely is. He should make it clear that they and their parties are to blame for what has gone wrong over the last five years in people’s cost of living, in the NHS and in a society where there all too often seems to be one rule for the rich and one for the rest. But Ed must not dwell too much on the failings of this government, but present a strong and positive vision of his own. Those watching will be explicitly looking for something different to what we have. Ed Must be able to offer them a realistic, realisable vision of a better future under Labour.

Ed should not be afraid to be clever tonight. If he is going to be genuine, he should show who he really is: a clever, likeable but geeky guy. He has odd passions that animate him (sadly, tonight will not be the time to talk about Manic Miner, but if you haven’t seen his interview with Absolute Radio you really should do) but many of those will be what Britain needs to rebuild our economy in a different way. Ed will need to pursue this argument fully. The energy price freeze is good. Banning non-doms is good. But the best part of our manifesto was not the shopping list of exemplars but the sense of a very real and different approach to government, to our economy and to society. Ed will need to express this vision tonight to those who are watching  in the hope of seeing something different.

In some ways tonight’s will be the most difficult of all the debates. There will be no David Cameron to challenge and no Nick Clegg to act as lightening rod for all the  anger many feel at the various betrayals of the Westminster system. Ed will have to act as a Prime Minister in waiting while equally offering a difference to Westminster as usual. He will need to appeal to those considering UKIP in Thurrock and those considering the SNP in Glasgow. He has been on the form of his life recently with his excellent performances in debates and speeches. Tonight will be the night for a slightly different approach – perhaps brainstorming over barnstorming. But if he pulls it off, this time without David Cameron going purple in the face as he hurls insults, Ed will come through the challenger pack not as head challenger but as the next Prime Minister.

Good luck Ed!