Tony Blair was among those who tried to persuade the young moderniser to stand for the leadership.

But as the Brown juggernaut careered towards No 10, Mr Miliband got cold feet and leaped out of the way.

"He was scared of what they would do to him," Mr Blair is said to have ruefully told a mutual ally at a dinner party, implying that Mr Miliband was afraid of falling victim to a smear campaign.

The impression that Mr Miliband lacked the killer instinct has hung around his neck ever since. Until today.

In a 900-word essay, he has published what reads like a leadership manifesto just as at the Prime Minister is facing a battle to survive in office.

There is nothing overtly disloyal in his words. But, between the lines, there are signals to Labour MPs that a potential replacement leader is in the wings.

What he said:

"In the aftermath of Labour's third successive defeat at the 1959 election, a famous pamphlet asked the question: 'Must Labour lose?' Today, the temptation is similar fatalism. We must not yield to it."

What he meant:

Mr Miliband is overtly addressing a mood among Labour MPs convinced they will lose the next election badly. But his words are being taken to refer to the pessimism about Gordon Brown's chances of avoiding a rout. By offering an alternative outlook, Mr Miliband plants the idea that he is capable of offering a fresh lead out of the rut.

What he didn't say:

The Foreign Secretary could have said that the Prime Minister has already given a lead and that Labour's fortunes will recover over the next two years along with the economy. This Brownite view has no place in his thinking.

What he said:

"I agree with Jack Straw that we don't need a summer of introspection. The starting point is not debating personalities but winning the argument about our record, our vision for the future and how we achieve it."

What he meant:

Mr Miliband namechecks Jack Straw, one of Labour's most seasoned operators. Rejecting introspection suggests he is against a lengthy debate about Mr Brown's leadership and the sentence is clearly intended to ensure he can say he was loyal in the article. However, it is far from a ringing endorsement of the PM.

What he didn't say:

Where is Gordon Brown's name? There is no mention of him nor any attempt to defend his leadership. This omission was read by Brownites as disloyalty.

What he said:

"To get our message across, we must be more humble about our shortcomings but more compelling about our achievements. With hindsight, we should have got on with reforming the NHS sooner. We needed better planning for how to win the peace in Iraq, not just win the war. We should have devolved more power away from Whitehall and Westminster. We needed a clearer drive towards becoming a lowcarbon, energy-efficient economy, not just to tackle climate change but to cut energy bills."

What he meant:

This is the most overt attack on the Brown record. Who blocked foundation hospitals and other NHS reforms pushed by Tony Blair? It was the former Chancellor and every Labour MP will read this as a recrimination. The criticism about Iraq falls on Mr Blair - but to Labour MPs it will be a welcome sign that Mr Miliband would be cautious about any future American adventurism. His criticism of the slow progress on devolution and low-carbon energy is a reminder that he, as Environment Secretary, championed both causes.

What he didn't say:

Where is the explanation for the slow pace of reforms on the NHS and other issues? By failing to excuse Mr Brown, he leaves hanging in the air that it was the Prime Minister's fault.

What he said:

"The problem with David Cameron is...he is a conservative, not a radical...I disagreed with Margaret Thatcher but at least it was clear what she stood for...What is his vision for Britain? He doesn't have one. His project is decontaminating the Tory party, not changing the country."

What he meant:

There is no point painting the Tory leader as a Thatcherite who would cut services and taxes for the rich. But the Conservatives can be beaten if Labour campaign as true modernisers who offer more change. That cannot be achieved by someone characterised by the Tory leader as "a roadblock to reform".

What he didn't say:

Conspicuously, absent is the phrase "as Gordon has shown us". He knows that among Labour MPs the most frequent criticism of No 10 is that it is still failing to explain what it stands for in words that voters can understand.

What he said:

"New Labour won three elections by offering real change, not just in policy but in the way we do politics. We must do so again. So let's stop feeling sorry for ourselves, enjoy a break, and then find the confidence to make our case afresh."

What he meant:

Labour won three elections under Tony Blair.

What he didn't say:

"And under Gordon's superb leadership, radical vision of change and sheer optimism, we will win for a fourth time!"