Why did Labour lose the election? An official inquiry will be published shortly, generating further debate as various factions within Labour and outside claim vindication for their own existing views. Here is my pre-emptive subjective explanation and it takes the form of a single event from almost exactly a year ago.

Last January the left-wing party Syriza won the general election in Greece. The result was confirmed on a Sunday evening. Within minutes the political consensus in much of the UK was clear. Tory and Lib Dem representatives from the Coalition and the media chorus all proclaimed it a disaster for Greece. For many hours though there was silence from Ed Miliband’s office. Not until early Monday afternoon was this statement issued. I re-publish it in its full, contorted evasiveness.

“Just like our elections are a matter for the people of this country, so who the Greek people elect is a decision for them. It is the responsibility of the British government to work with the elected government of Greece for the good of Britain and Europe and not to play politics. And it is up to each country to choose its own path on how to deal with the economic and social challenges they face. We have set out our path for Britain: to make sure our country is fairer and more prosperous and balance the books.”

In that short sequence, the delay over its appearance, the evasive words in relation to Syriza, the nervously anti-climactic ending, is at least part of the explanation as to why Labour lost the last election. The reason for the delay was that Miliband’s office could not agree how to respond. Some aides were excited by Syriza’s success. I imagine Miliband’s instinctive response was similarly positive. But others pointed out that they could not display a hint of enthusiasm because Labour’s position was to be almost as tough on public spending as George Osborne. Finally Miliband’s office issued the statement that avoided either hailing or condemning the election of Syriza but adding, in case anyone wondered, it was Labour’s priority to “balance the books”.

Part of Miliband and some in his entourage ached to leap on the political energy unleashed in Greece, while another part of Miliband and several aides sought total distance. The torment was symptomatic. They never resolved the tension and the lack of clarity had many consequences from periods of media inactivity to blurred messages about whether Labour stood for radical change or one in which it identified the UK as a rotting castle in which it proposed to do little more than change the ashtrays.

The failure to resolve the dilemma had many consequences. In the final stages of the referendum in Scotland several voters told me, wrongly, that they thought David Cameron and Miliband were “the same”. If Scots had known what Miliband really felt about what was wrong with the UK and what he would do about it he might at the least have got an audience. But they picked up the message about Labour planning to do no more than change the ashtrays.

Conversely Miliband’s many opponents in England heard the other message, that he was a dangerous leftwinger. Militant Blairites attacked him around the clock, together with Lynton Crosby’s brilliantly disciplined Tory campaign fuelling a sense that Labour was fiscally reckless.

The opposite was closer to the truth. Labour’s “tax and spend” plans were even more bomb-proofed than in 1997. The Shadow Chancellor, Ed Balls, worked around the clock to make sure that not a halfpenny was uncosted. For five years no Shadow Cabinet member was allowed to utter a word that implied a spending commitment. In comparison Cameron and Osborne were profligate. During Cameron’s pre-election conference speech he proposed a series of tax cuts without any explanation as to how they would be paid for. Early in the election the duo pledged a seven-day NHS without knowing how it would be funded.

While not getting any credit for fiscal discipline, Labour’s attempt at rectitude stifled visionary ideas such as the introduction of a national care service, a proposition that for selfish reasons every voter should be crying out for.

The sense that a reckless minority Labour government would be held ransom by the SNP was the final nail, a very big one. Here media bias played a significant role. On the day Labour highlighted its tough tax and spending plans the Tories launched a poster campaign featuring a tiny Miliband in the shirt pocket of Alex Salmond. The Times splashed its front page with the poster and the theme of Labour being in the pocket of the SNP. When the shadow chief secretary, Chris Leslie, appeared on the Today programme to launch Labour’s plans for the economy on the same morning, he was asked only about the SNP. It was all nonsense. Any minority government would have been in the hands of the SNP. But the prospect killed off Labour and hugely helped the Conservatives.

What are the lessons? Clarity and an accompanying narrative are incredibly important. Currently Jeremy Corbyn is stronger than his internal opponents not only because he won the leadership by a landslide. He knows what he stands for while his enemies huff and puff vaguely. Smart presentation is essential, framing arguments with a wide appeal. Few follow politics closely. The still powerful media mediates.