Despite observations that Ed Miliband’s fight to hold the keys to 10 Downing Street in May next year is getting tougher by the day, the Labour leader’s closest advisers have no doubt they are working for the man who will become the next Prime Minister, and whose opponents underestimate him at their peril.

There have been some admittedly vigorous headwinds.

A heavily criticised conference speech, in which he failed to mention the deficit or immigration, was preceded by a barely noticed intervention in the Scottish independence debate. Earlier this month, a by-election in the usually comfortable Labour seat of Heywood & Middleton in Greater Manchester saw UKIP come within 618 votes of inflicting a political decapitation.

But a couple of effective performances at Prime Minister’s Questions since then, one featuring a classic New Labour-style ambush which offered a reminder of Miliband’s ruthless edge, and a widely welcomed recent announcement on new homes in London, have stymied some of the criticism. However, this stabilisation has not entirely quietened the rumblings about Miliband’s leadership in some quarters of the party.

There remains the risk of an autumn of discontent unfolding on the Labour backbenches and even amongst the shadow cabinet. There will be no outright mutiny, yet Miliband clearly does not enjoy the unqualified confidence of his party with just under 200 days to go until the general election.

Criticism from within the ranks reflects disappointment that the party’s poll lead over the Conservatives has not stretched beyond a few percentage points and there are concerns that the personally targeted barrage from sections of the media is registering with some voters, as are lingering doubts about the party’s economic competence.

While team Miliband is acutely aware of the criticisms and multiple threats to its bid to win power next year, there is a quiet confidence in the substantive policy offer being made by their leader.

The narrative being delivered to the electorate by his opponents is that Miliband doesn’t look like a Prime Minister-in-waiting, and that Labour simply can’t be trusted on the economy. Polls indicate that the tactic has gained some traction, with the Conservatives comfortably ahead on both measures.

While team Miliband is acutely aware of these criticisms and the multiple threats to its bid to win power next year, there is a quiet confidence that the substantive policy offer being made by their leader to the electorate is strong enough and broad enough to win enough seats at the general election to form a Labour government come the spring.

Polling shows that the issues of most importance to voters are 1) the NHS, 2) immigration, and 3) jobs and wages. Labour scores highly when it comes to the NHS and jobs. David Cameron’s recent attempts to challenge Labour’s dominance on the health service have been dismissed as unsuccessful, and the party’s lead on jobs and wages is seen as a vindication of Miliband’s continued emphasis on his signature theme of the cost of living crisis. Voters also view the Labour party as fairer than the Conservatives and Miliband as a more connected politician than Cameron.

On a less firm footing is Labour’s immigration policy, where voters remain distrustful. Yet those close to Miliband argue that Cameron’s rightward shift on the issue in reaction to UKIP, and the Liberal Democrats’ dwindling credibility as a political entity which is able to engage voters, leaves an unoccupied space on the all-important centre-ground of British politics which Miliband can exploit.

The Labour leadership’s strategy in the run-up to the election is to paint Nick Clegg as a spent force and his party as one lacking credibility, while portraying David Cameron and Nigel Farage as two leaders locked in a mortal combat to command outlying ground on the electoral battlefield, especially on immigration and the wider issue of Britain’s membership of the EU. Miliband’s view is that while there are problems with the current immigration system in the UK which need to be addressed, Cameron’s showdown with the EU on a founding principle of free movement exposes him to the risk of being unable to offer outcomes that match his bellicose rhetoric. In the eyes of the centre-ground waverers, the Prime Minister’s position effectively leaves Labour as the only major political party which is both sensible and credible when it comes to achieving realistic EU reform. Much like the media’s reporting of Miliband’s personality, his camp believes that the press coverage does not represent the reality of opinion held by a significant part of the electorate, which is generally moderate and reasonable on these issues and will make its voice heard on polling day. The strategy explains Pat McFadden’s recent appointment as shadow Europe minister, a former member of the Treasury Select Committee who also served a business minister in the Brown government. Well-versed in economic policy and measured in his manner, McFadden’s task will be to deliver the “hard-headed, patriotic case” for Britain to remain the EU.

The team also acknowledges the often repeated argument that the economy will be the key issue for voters and determine who takes power in May. However, Miliband argues that while the coalition’s claims to have delivered an economic recovery may be true in aggregate terms, this fact, crucially, has not translated into rising wages or increased job security for workers. The Labour leader’s advisers explain that this is due to the weak foundations of the overall recovery, which they say entails a dangerous cocktail of consumption-based growth that is adding to already high levels of household debt, and an out-of-control housing market. The Miliband critique could gain further traction if the economy slows sharply over the remaining months before the election.

There exists a conviction in the leader’s office that an empathetic Ed Miliband, perceived to be ‘in touch’ on the economy, sympathetic to the public demand for the reform of private markets, while sensible and reasonable on the EU and immigration, will persuade the centre ground that their interests lie in voting Labour.

Miliband’s solution, however, dismisses a return to old Labour orthodoxies which voters have consistently rejected in the past, where a tax and spend model provides the basis for approaches to public investment and growth. Insiders describe the preferred strategy as one which emphasises a ‘supply-side agenda’. The focus will be on reforming both public and private institutions, increasing competition and regulator efficacy in markets, ensuring long-termism in decision-making around infrastructure projects and providing stability for businesses.

To say that the voters will cast their ballots primarily on the issue of the economy is axiomatic – the question is whether they will do so based on their own economic circumstances or on their understanding of the country’s overall growth numbers. Miliband’s assessment is that the Government’s periodic trumpeting of increased headline growth in UK GDP is evidence of a wider disconnect between the Conservatives and the electorate, who aren’t seeing much of an economic trickle-down. He believes that falling wages, increased workplace insecurity and the rising cost of living will swing the vote in his favour.

The mooted television debates ahead of the general election are being seen by Miliband’s team as an opportunity for the Labour leader to speak directly to the electorate and address their key concerns. There exists a conviction in the leader’s office that an empathetic Ed Miliband who is perceived to be ‘in touch’ on the economy, sympathetic to the public demand for the reform of private markets, while sensible and reasonable on the EU and immigration, will persuade the electorally crucial undecideds on the centre ground that their interests, and those of the nation, lie in voting Labour.

There are numerous potential pitfalls and unknowns that Miliband and his team will have to navigate between now and 7 May. Global economic uncertainty poses domestic risks in a fiscal form that the party will have to speak to comfortably, and the rise of UKIP presents a clear threat to its hegemony in neglected heartlands. Yet the path to power is seldom an easy one, and his team knows that underestimating Ed Miliband is the one mistake his political opponents most regret making.