Memory man Ed Miliband remembers 6000-word speech by dividing it into 11 sections

As the Labour leader basked in plaudits for speaking for 65 minutes without notes, he insisted the technique demonstrated his authenticity. He said: “In the end, if you really believe something you don’t need [a text].”

The seeds of the speech, which his aides claimed could prove to be a political “game-changer”, were sown exactly a year ago after his coolly-received address to the 2011 conference. He walked off stage in Liverpool and remarked to his team that he could have delivered the same comments – and to greater effect - without an autocue.

Mr Miliband started work on this year’s speech – initially intended to run to 5,000 words and to last 50 minutes – while on holiday in Greece.

After deciding on the broad outline of his message to activists, he divided his planned comments into 11 sections of five minutes each, including “my story”, “two nations” and “Olympic spirit”.

He consigned each to memory, but only ran through his planned speech in its entirety five or six times before his appearance in Manchester yesterday.

A colleague said today that every time he practised the speech it came out slightly differently.

“The idea was to make sure Ed had a connection with people, that he said what he felt rather than what he learnt,” he said.

In the end the Labour leader spoke for 15 minutes more than he planned and uttered an extra 1,500 words, increasing the workload of staff who transcribed the address.

There were some downsides to the technique. To the dismay of green groups, he forgot to mention the environment – an omission he corrected in a question and answer session at the conference today. He also worked in some unused material about the health of the party.

The Labour team has learnt from David Cameron over the impact that a memorised speech, delivered while striding the conference stage, can have on an audience.

But there was one Cameron method for producing compelling conference oratory that Mr Miliband avoided.

The Prime Minister is known to deliver speeches on a full bladder, producing an inner tension that keeps the party faithful gripped. For all his apparent outward calm, the Labour leader did not need to add to his nerves.