Ed Miliband knows he can beat David Cameron. Miliband has long prepared for the now elusive chance to go head to head with the PM.

But the closest Miliband will get to that moment is Thursday’s interview with Paxman and a studio audience, following Cameron’s own grilling, and the “leaders’ debate” – or multi-candidate pile-up as it might more accurately be described – on 2 April.

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Nonetheless, Team Miliband will give these events their all, trusting in Miliband’s own formidable intellect and benefiting from lower media expectations than other leaders might experience.

Behind the scenes, debate preparation is a flurry of briefing books, statistics memorisation and scenario responses. The amount of information party leaders are expected to know by heart is ridiculous: as if the prime minister must make decisions on the NHS or housebuilding budgets based on memory alone without recourse to notes or aides. But the standards by which victory will be judged include instant recall of minutiae and Team Miliband will prepare accordingly. Fortunately, the self-confessed baseball statistics geek should have no problem knowing his sums on the night.

The next challenge in debate preparation is war-gaming question and answer scenarios. Candidates will go through dozens of question-response drills. For example: if asked about falling unemployment statistics, answer with a story that illustrates the youth unemployment problem; if asked about defence cuts, the answer must include reference to Putin’s Russia and concern over Islamic State, etc.

This is where mock debates can be both help and hindrance. Get the questioner’s line of attack right in advance and answering can feel like a walk in the park. But misjudge the tone or appear robotic as memory spits out pre-canned lines, and the danger of not connecting with the audience is serious indeed.

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The mock debate preparations, with trusted aides and even friends playing the part of moderator or opponent, allow the candidate to find the right balance between knowledge and emotion. For this, Miliband will benefit from the extensive debating experience of his campaign chief, Douglas Alexander, in planning his moves and countermoves. That said, Miliband must also guard against over-preparation or too many voices offering differing advice if he is to deliver his core message cleanly.

Because through it all, amid the stats, stories and prepared lines, the leaders will be constantly harangued to “stay authentic”, “stick to your core script” and “be on message”.

For Miliband, that means sticking to his brand as a leader of substance not spin, a man who prizes policy over PR. His core script is about the choice before the electorate of a Britain run by a few people at the top of government and companies for the benefit of a few people at the top of society and the economy alike versus a Labour party that stands for the many, not the few.

This gets to the driving idea behind Miliband’s politics: a passionate desire to reduce inequality in the economy and society as a whole. It is this central message that the ex-Obama guru David Axelrod has encouraged Miliband to stick to, not just because it resonates with the voters Labour needs but because it accurately reflects Miliband’s personal rationale for politics itself.

The need to stay on message and deliver the soundbites that the focus groups and messaging gurus assure the leaders go down well with key voter groups will weigh heavily on the protagonists’ minds. For Miliband that means a soundbite-packed greatest hits album of “same old Tories”, “NHS under threat” and “cost of living crisis”. Don’t expect to see loftier ideas like “one nation” or policywonk thoughts on “predistribution” on prime-time TV.

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Finally, most irritating of all to the spinners and coaches who specialise in the craft of high-stakes leaders’ debate, there is the need to “win” the debate not merely in terms of debating points to please the insta-reaction TV pundits and next-day newspaper columnists, but with the voters themselves. What can seem like a clever exchange on stage may go down badly with the public, as Al Gore discovered when debating George W Bush in 2000: hyper-aggression and detailed policy knowledge win debating points rather than votes.

Preparing properly, adapting to different debating formats, meeting the messaging challenges, keeping to a core script and winning the voters’ hearts and minds – victory in the debates is no mean task. Yet with a strong team and his own natural gifts, Miliband has more reason to look with confidence rather than trepidation to the clashes ahead.

Marcus Roberts is deputy general secretary of the Fabian Society