An always tense, sometimes disjointed and occasionally cacophonous seven-way live TV leaders debate saw Ed Miliband just shave ahead of his rivals, according to a snap Guardian/ICM poll conducted after the event, reports The Guardian.

Labour, aware of Miliband’s poor personal ratings before the campaign, will be pleased he was at least matching the normally more popular David Cameron, according to ICM and the three other post-debate polls.

Miliband branded the prime minister as an invisible man who said little in the two-hour debate on ITV. But the prime minister will be pleased that he emerged from a safety-first performance largely unscathed from his only head-to-head television clash with Miliband.

Cameron, remaining calm under sustained attack, drove home the central message of the Tory campaign and even stole a line favoured by Miliband, saying: ‘The choice at this election is sticking with the plan that’s working, or going back to the debt, taxes, borrowing and spending that got us in this mess in the first place. I say let’s not go back to square one; Britain can do so much better than that.’

The Guardian/ICM post-debate poll showed that Miliband won the debate by a whisker over Cameron – by 25% to 24%. Ukip’s Nigel Farage came third on 19%, the Scottish National party leader Nicola Sturgeon was fourth on 17%, with the Liberal Democrats leader Nick Clegg trailing in fifth place on 9%, ahead of Natalie Bennett for the Greens on 3% and Plaid Cymru’s Leanne Wood on 2%.

But Cameron and Miliband were in a dead heat – 50% to 50% – when voters were asked to choose simply between the leader of the two parties.

Miliband, rarely attacked in public from the left and eager to focus on presenting himself as an alternative prime minister, initially struggled to find the room in a crowded multi-party debate to sharpen his attack on Cameron.

However, he found his voice when he mounted a strong personal assault on Cameron’s stewardship of the NHS and Cameron’s zero-hours economy.