There is a new division in the Labour party. It is between those who want Ed Miliband to change the way he leads, and those who accept that he won’t. The old feuds, between defenders of Tony Blair, ex-acolytes of Gordon Brown and a nostalgic left that sees New Labour as a virus in the body of true socialism, are in temporary abeyance before the more pressing task of beating the Tories.

Even supporters of Miliband’s approach – those who welcomed his ambition to “turn the page” on the past and who engaged constructively with his “one nation” project – roam parliament with looks of glassy-eyed dismay. The party’s lacklustre conference, culminating in a bungled leader’s speech, ended any remaining hope that Miliband might illuminate his vision of a Labour-run Britain for a wider audience. “We languished in the comfort zone,” says one shadow minister. “It hardly felt like a party. It felt like a cult.”

Then came the Heywood and Middleton byelection. Coming within a few hundred votes of losing a safe seat to Ukip turned anxiety to terror. Shadow ministers who could once be relied on to defend Miliband now talk about what might be salvaged from this parliament and used to rebuild in the next one. Their fear is that sound strategic choices and shrewd economic analysis – the emphasis on a cost-of-living crisis and its explanation in terms of systemic flaws in the way Britain’s economy distributes reward – will be discredited because the man who formulated the ideas can’t express them as a battle cry.

The clamour for change is focused on two areas – message and personnel. There is a battle under way to make sure the 2015 manifesto reflects the work Jon Cruddas has put into Labour’s policy review. His supporters are frustrated that Miliband commissioned what they see as an imaginative, wide-ranging blueprint for government yet now seems determined to fight the election on the narrowest of terrain. They want a programme of unflinching reform of the state, based on local devolution and the aspiration to give citizens more control over public services.

Others who are less wedded to the detail of the policy review nonetheless agree that Labour is failing to make the case for politics that can make a difference in people’s lives at a time when voters are viscerally suspicious of all Westminster politicians and well aware that budgets are tight.

Instead, say the reformers, Miliband has toyed with radicalism only to retreat behind hackneyed attack lines against the Tories as tax cutters for millionaires and NHS saboteurs. It is widely expected that the manifesto will be a cautious affair, put together by the wonks in the leader’s office, with droplets from the policy review added for flavour – closely resembling the document Miliband himself compiled for the last election. “We’re going back to 2010,” says one despondent adviser.

On personnel there is no move to unseat the leader, although some indulge the fantasy of the former home secretary Alan Johnson appearing as deus ex machina, radiating the blokeish, working-class authenticity the front bench conspicuously lacks. “The only viable alternative is Alan and he’s ruled himself out,” says one shadow minister, “so we’re stuck with what we’ve got.”

There is still talk of “bringing back AJ” in some other campaigning capacity – connecting with voters who like a politician who can show signs of life beyond Westminster; a roving spokesman with hinterland. But the leader’s office is desperate not to concede that Miliband is a weak messenger.

Shadow ministers complain of having their voices stifled. Their articles are vetted and purged of interesting content. At the party conference they were instructed not to announce policy. Some were told to limit speeches to 700 words. The motive commonly ascribed to such control is fear that anyone who shines will be talked up as a leadership contender, as if the way to big up Miliband is to shrink imagined rivals. (“They need to bloody well get over that,” says one senior figure.)

This tension is hobbling the march on power. Much of the party thinks they should be running on a team ticket, mobilising the residual strength of the Labour brand and using shadow ministers to sell a rich policy platform. But the players in that team suspect the management is determined to prove that the game can be won their way, with only the captain scoring the goals. Stubborn pride, say the critics, is trumping strategic reality.

But Labour is still ahead in the polls. Miliband aides insist that victory is well within reach and that the core message – “for the many not the few” – is a big hit with target voters. At a meeting of Labour MPs on Monday, Miliband confronted fear of the advantage “slipping away” and pledged to “strain every sinew” in the coming months. There was no rebellious combustion.

Habitual sceptics say they were heartened by signs that the leadership is taking the Ukip threat seriously. “He showed some real fire on that,” says one backbencher. Others suspect the collegiate mood was a symptom of wagons being circled as the election nears. Some no longer bother voicing dissent – or even turning up to such gatherings when time would be better spent in their constituencies.

Loyalty now mostly means doggedly clawing back territory from the Tories, in a seat-by-seat ground operation with little expectation of air cover. MPs who campaigned in Heywood and Middleton say the seat would have been lost were it not for the agility and energy of local organisers. “They are what give us hope for the marginals,” says one frontbencher. “The leader and the strategy aren’t going to change. We’ve got what we’ve got and have to make the best of it,” says another.

The plan, as most Labour MPs see it, is to piece together an agenda for government after the election – ideally with a majority, more likely in a hung parliament – or the work done so far will be a resource for the next leader.

Miliband deserves credit for starting the conversation the party needed to have about the path to renewal after the calamity of 2010. There have been flashes of inspiration to light the way. But the conversation is unfinished and inspiration is on hold while the party scrambles to miss its second appointment with defeat.