If the Labour Party wants an outside perspective on the reasons for its calamitous performance at the last election it could start by comparing itself to the Liberal Party. Doing so may not hold instinctive appeal, but historians have long debated why the Liberal Party, having been the dominant force in the hundred years preceding 1922, went into rapid decline and the approach holds true for Labour now.

One camp argues that the Liberals fell victim to a great historic process – the rise of trade union membership and a Labour Party to represent it in Parliament. There was not much that the Liberals could do about this inevitable shift, given that the Conservatives were better placed to be the anti-Labour alternative.

The other camp of historians thinks that this strategic inevitability argument is over-stated. They argue Liberal decline had much more to do with personalities and their propensity for backstabbing than historical determinism. Basically, the two foremost Liberal politicians, Asquith and Lloyd George, fell out and effectively broke the bones of their once great party in an internecine punch-up. Labour stepped over the bloodied body, and successfully positioned itself as the more disciplined and effectual alternative to the Conservatives.

Seven months after the Labour Party was decisively rejected in the December 2019 general election, a similar dichotomy in how to interpet its loss must be addressed. Should the Party conclude that the reasons for its defeat were strategic (the long-term decline in the institutions and beliefs that bonded a solid adherence of working people to the Labour movement) or tactical (a poor election strategy, promoting the wrong policies, fronted by a leader with narrow appeal)? Bad tactics, policies and personalities can be rectified in the course of one electoral cycle, but structural decline represents a more serious threat.

To assess what went wrong and how it could be put right, the election review commissioned by Labour Together, a network of activists from across the traditions and institutions of the Labour movement, was published on Friday.

A party that has recently received a pasting is often not in the right frame of mind to take a cool look at the short and long term reasons. Finding scapegoats is more cathartic. But however tempting to settle scores, Labour Together has instead lived up to its name. Measured in verdict and considered in tone, its report is the work of a panel of 14 commissioners (plus one collective) spanning a wide spread of experienced voices (among whom, Ed Miliband). Their findings are informed by extensive surveying and out-sourced data analysis and should be of interest to anyone trying to make sense of the contemporary political landscape.

Where to begin? After their defeat, generals are often accused of having attempted to refight their previous war. “The absence of an objective and open review of our 2017 general election loss” the Labour Together report believes, “was a key strategic error for Labour.”  In areas like digital strategy, the Conservatives learned from their mistakes in 2017 and upped their game two years later. Their strategy focused on swing voters. Proud of its 2017 performance, Labour did not recalibrate, and wasted too much online resources facilitating social media exchanges within its own support base.

Indeed, an inference to be taken from Labour Together’s report is a clear temptation to see the strong performance in 2017 as a mixed blessing. The party’s gains (albeit shy of victory) in that contest were pulled off in the exceptional circumstances of a Corbyn surge against a mesmerisingly hapless Tory campaigner. This strong showing masked what was, in reailty, a long underlying decay in Labour’s position. The 2019 poll pitilessly exposed the reality.

It can also be inferred that the 2017 experience of making rapid polling advances in a matter of weeks gave Labour tacticians in 2019 hope that they could reprise the dashing cavalry charge, and that they were fighting an offensive, rather than defensive war. Resources were consequently spread broadly where they might have been better targeted defending vulnerable seats. Psychologically too, 2017’s strong showing encouraged those close to Corbyn to believe that the forces of history were moving inexorably in their direction. Just one more heave! Whereas, in truth, the tide was receding.

the party’s defeat was caused neither by the unique circumstances of 2019 nor by long term socio-economic and group shifts – but by both

Labour Together’s report avoids name calling but does not avoid facing facts. “Among voters who switched from Labour to the Conservatives, concern about Jeremy Corbyn was intense, whichever way they voted in the [Brexit] referendum” it concludes. Secondly, “the Tories won the 2019 election primarily by consolidating the Leave vote.” This was not just about voters switching allegiances. Importantly, a strata of the electorate that had got out of the voting habit during the Blair and Brown years returned to the polls to vote in the 2016 EU referendum and continued to do so in the two subsequent general elections, partly in 2017 and convincingly last year. These formerly “lost” voters now turn out for the Conservatives.

The report is short on optimism, but there was much in the circumstances of 2019 that are unlikely to be repeated when the country next goes to the polls in 2023 or 2024. The first is that Labour is no longer led by someone who could be painted as a security risk. Secondly, the “Get Brexit Done” message, which offered a country weary of the bickering and Westminster politics of the previous three years the prospect of moving on, cannot be revived next time. However smooth or turbulent the UK’s initial experience of being outside the EU proves, frustrated voters will not be turning out to deliver it all over again.

Starmer has sensibly spent his first weeks trying to reunite his party (on his terms and personnel) and conveying a measured and reasonable demeanour to the wider electorate in a time of national anxiety. Policy development is for another day. One big change since 2019 is that the Conservatives have become a ‘Big State’ party, intentionally (infrastructure projects) and unintentionally (paying for the Coronavirus lockdown). By 2023 or 2024 will the electorate be in the mood for more of this or less of this? The unforeseeable state of the economy by then may tilt them either way. The starting place for the debate will be very different for both parties.

Labour Together’s report concludes that the party’s defeat was caused neither by the unique circumstances of 2019 nor by long term socio-economic and group shifts – but by both. Which, obviously, is the worst of both worlds and gives no grounds for a rapid recovery, even if the latest polls show the beginning of this process.

The weakening of a coherently Labour working class identity through deindustrialization, falling union membership (outside the public sector), social mobility and fracturing of once coherent communities has, as the report attests, been going on since the 1980s. It did not stop Labour enjoying landslides in 1997 and 2001 at a time when the party’s leadership was signaling its removal from these traditions. The report calls for the party to re-embed itself in working class communities who believe Labour has become remote from them. Difficult to disagree with, this is nevertheless easier said than done. Yet, the reader feels the sense of loss felt in the report’s statement, “We were rejected by many of the communities we were founded to represent.” Labour now has more middle class voters than working class ones, but their predominance in London and the other urban heartlands entails votes piling-up in safe seats. Apart from in university cities (where the LibDems are the rival) the battle for the market towns, let alone the countryside, is all but ceded to the Conservatives.

Recreating a mass movement, embedded in communities would be a help. But, if mass membership was the only key to Downing Street, Jeremy Corbyn would now be masterminding the nation’s Coronavirus response. If he achieved nothing else, he was good at encouraging participation in the Labour movement. Whereas Labour had comfortably more than half a million members, the Conservatives (on 2018 statistics) only had about 125,000 members (many aged beyond active service) – almost exactly the same number as the SNP.

In Britain, as in much of the democratic world, voter volatility is increasing. This worked decisively against Labour in 2019, but on the principle of what goes around comes around, it could easily swing back next time. Whilst no precedent exists for Labour making the sort of comeback within five years that would be required to form the next government, this is one area where historical precedent might not have the last word. Of great potential is the overwhelming allegiance of young voters not only to Labour but to a progressive world view that could mean they will not grow into Tories in later life. It is often claimed that the young have always been radicals, but the polling does not demonstrate this to be true – it has only become decisive in the last two elections. Labour should take heart that here is one part of the demography that worries the wits out of the Conservatives far more than it does any other party.

Where the report paints a particularly stark picture is Scotland and the speed with which Labour went in the aftermath of the Scottish independence referendum from the dominant force to third place behind the Tories is a major reason for why the party lost so badly nationwide in 2019. The rise of the SNP has turned Scottish politics into a battleground between nationalists and unionists, leading many working class Scots to put aside their doubts about the Tories and to back them as the surest bulwark against the breakup of the UK. Perhaps because the integrity of the UK was never one of his passions, Corbyn simply did not get this reality and played into SNP hands with his equivocal stance on whether another referendum could be offered. The report is unambigious on this point, stating, “Labour should get behind the resolved position on no new independence referendum set out by our new leadership.”

Labour Together’s report does its best not to blow the embers of internecine discord more than the facts make inevitable. There is little in it that does not tie with what Keir Starmer seeks to achieve, and in the purging of Corbynistas that has already taken place he has begun the task, although in the promotion of which policies nobody yet can tell.

Writing in Tribune, former shadow ministers, Ian Lavery and Jon Trickett, have been quick to criticize those aspects of the report that suggest Corbyn and  socialism scared off voters. The socialist policies were not unpopular, merely there was widespread scepticism that they would be implemented. Corbyn had shown his popularity in 2017 but the attacks on him proved too relentless to counter by 2019 – not least from within his own party.

Indeed, data in the report does show that Corbyn’s popularity slumped significantly during early 2019 when centrist Labour MPs like Chuka Umunna and Luciana Berger left the party to set up the Independent Group (subsequently ChangeUK). But the Corbyn-loyalists, Lavery and Trickett, go further, “we argued that those colleagues who used their senior position in the Shadow Cabinet then to publicly advocate a second referendum with remain as Labour’s favoured option in order to appease their own heavily remain urban electorates were damaging our national standing.”

This is a not very subtle jab at Keir Starmer, who was central to the second referendum position being adopted. In this sense, he certainly cannot plausibly blame all his party’s woes on the Corbynistas he has now replaced. But whilst history should record his mistake, it is possible he has already learned from it. Can the same be said of Momentum?