Keir Starmer has inherited a poisonous legacy from Jeremy Corbyn. Despite his resounding victory in the first round of the Labour leadership contest, the new leader faces a daunting challenge after the recent years of division and extremism which have so alienated the electorate. Yet Labour’s internal problems are more than counterbalanced by the deepening troubles faced by Boris Johnson’s Conservatives. In the wake of the coronavirus crisis, the tide of public opinion is bound to shift dramatically against the Tories. Indeed, Labour’s advance will be so large that a victory at the next general election in 2024 looks almost a certainty. Strengthened by the scale of his leadership triumph, which gives him a powerful mandate, Starmer may well be on his way to Downing Street.

To some, that prediction might seem absurd. After all Labour suffered a humiliating defeat at the polls only four months ago, their fourth successive loss in nine years. To win an overall majority, Starmer’s party will have to gain at least 120 seats next time, a colossal task given that vast swathes of traditional Labour territory in Scotland, the North and Midlands are now held by the Conservatives. The recent wipeout in Scotland is all the more damaging because Labour has not won the popular vote in England since 2001.

Moreover, in the present hour of darkness, the nation appears to be rallying behind Johnson’s Government. An opinion poll last week gave the Tories a lead over Labour of 24 per cent, while another in late March put them 26 per cent ahead, the biggest gap since the Falklands War in 1982. At 54 per cent, Johnson’s party enjoyed their largest-ever share of the vote in office. Despite his illness from Covid-19, Johnson is more popular than ever, with 72 per cent of the public expressing satisfaction with his performance.

But these ratings are unsustainable. Already the government is under immense pressure because of accusations that ministers have badly mishandled their response to the pandemic. The entire official strategy looks increasingly shambolic. There is a swelling chorus of disapproval over the inadequacy of the testing regime, the failure to provide sufficient personal protection equipment to emergency staff, the gaping holes in the Chancellor’s financial safety net, the late implementation of the lockdown and the confusion over safety messages. Once the emergency has passed, the Tory government will inevitably be subjected to a barrage of angry recriminations, particularly if Britain’s death toll is proportionately higher than in other Western countries. The mood of indignation will be further fuelled by economic meltdown on a scale never seen before, not even during the Great Depression. Amid soaring unemployment, home repossessions, business collapses, ruined public finances and rising poverty, Covid-19 will become a weapon of mass destruction against the Tories.

It is almost a law of British politics that incumbent governments are punished, however unfairly, for significant domestic crises. That was true of Harold Wilson, who lost the 1970 general election after the devaluation of the pound, and his successor Ted Heath, defeated in February 1974 in the wake of the three-day week. Jim Callaghan lost in 1979 after the Winter of Discontent, John Major in 1997 after Black Wednesday and Gordon Brown in 2010 after the financial crash. It is impossible to see how Boris Johnson will break that pattern. The one exception to this rule is 1931, when Ramsay MacDonald was returned after the economic crisis, but that was only because of the unique circumstances in which he created a National Government and hopelessly split his own party in the process.

Labour’s journey back to power will also be helped by the fact that, by 2024, the Tories will have been in office for 14 years, testing public patience to the limit. The very nature of parliamentary democracy demands a swing of the pendulum, otherwise we are burdened with one-party governance. More importantly, the policies the government has been forced to adopt during this crisis are essentially left wing. The classic, free-market model looks hopelessly outdated in a broken economy that requires massive public expenditure, nationalisation, heavy wage subsidies, and extended welfare. Margaret Thatcher once said that “the facts of life invariably turn out to be Conservative,” but that is not true in this case. It is the Labour Party’s most cherished beliefs, like support for the NHS, that now prevail.

There is a striking parallel with 1945, when Labour under Clement Attlee won by a landslide against Winston Churchill’s Conservatives largely because the war had promoted widespread faith in the central role of the state in British life. In a sense, peacetime socialism was simply the extension of the wartime economy, with its emphasis on central planning and controls. Tory scaremongering about left-wing economics carried little weight among a public that had experienced food rationing, the conscription of labour, restrictions on profits and unprecedented levels of state expenditure. In 1938, public spending accounted for 28.9 per cent of GDP, a figure that rose to 70.3 per cent by 1945. By the time of the election, Attlee’s radicalism was seen as mainstream, even patriotic. As the historian and former Labour MP David Marquand put it in a New Statesman article in 2016, “war socialism transformed the public culture. Pre-war heresies came in from the cold and “were absorbed into conventional wisdom.”

Starmer’s landslide victory will further strengthen the idea that Labour has returned to the political mainstream. With the end of Corbynism, the party will no longer look like an ideological personality cult, but instead will be viewed as a serious alternative government. Some Tories are complacent, viewing Starmer as either too boring or too left-wing to appeal to the British public. “Ed Miliband with a knighthood,” runs one typical jibe. There is also the claim that he will not be able to win back Labour’s Brexit-voting heartlands both because of his strong pro-Remain views and his position as a London MP.

But much this amounts to dangerous wishful thinking. By 2024, Brexit will be a supreme irrelevance. As a political issue, it will be dwarfed by the devastating fallout from the coronavirus crisis. On a personal level, Starmer, the son of a toolmaker and a nurse, can hardly be described as a member of the metropolitan elite. Furthermore, he will represent a formidable challenge to Boris Johnson, especially at the despatch box in the House of Commons where he has shown his gift for forensic detail. Outside Parliament, he could turn out to be better performer than critics believe, as shown by his acceptance speech on Saturday (4 April), which was well-constructed and persuasive.

The new Labour leader might lack charisma, but he more than makes up for that with his intelligence, industry and integrity. In these respects, he resembles Attlee, whose patent decency and reliability had more appeal to the British electorate than Churchill’s stardust in 1945.

One of the most persistent complaints about the modern politicians is that most of them are just professional place-seekers, who lack any wider experience of the real world because of their careerist focus on moving up their party’s hierarchy. But Starmer is very different. As the former director of public prosecutions, he held one of the biggest jobs in British public life, winning widespread praise for the assured way he handled the responsibility. One friend of mine, who is a lawyer and describes himself as a “natural Tory”, told me last week that he would probably vote Labour because of his admiration for the new leader.

Labour’s revival after the dark years of Corbyn will be reinforced by the likely return of talent to the frontbench. Political ability will count for more than ideological devotion under Starmer’s leadership which could see big, experienced figures back in the fold, such as Hilary Benn, Rachel Reeves, Pat McFadden and Yvette Cooper. With the noisy, hard-left lightweights such as Richard Burgon banished to the wilderness where they belong, the shadow cabinet will regain its credibility.

Despite these likely changes, it will still be argued that Labour faces an impossible task, in view of the Tories’ 80-seat majority. But in reality, the job facing Labour should not be exaggerated or regarded as uniquely intimidating. In the 1959 general election under Hugh Gaitskell, Labour ended up with 107 fewer seats than the Tories, prompting some moderates to call for the party to change its name, such was their despair. Yet within five years, under Wilson, Labour was back in power. After the 2005 general election, Labour had 157 more MPs than the Tories, yet David Cameron rode to victory in 2010 by making 96 gains on a swing of just 3.7 per cent. In a political landscape that will have been transformed by the coronavirus pandemic, that kind of achievement should easily be in Labour’s grasp. Even Corbyn, one of the most ineffectual leaders in modern British political history, achieved a rise in his party’s vote share of 9.6 per cent at the 2017 general election.

For all drama of Boris Johnson’s win in December last year, it should be noted that the Tory majority is vulnerable. No fewer than 67 Tory seats would fall in 2024 on a swing of less than 5 per cent, most of them Labour targets. Sixteen Conservative marginals have majorities of less than 1,000 votes, including a host of constituencies that once made up the so-called “Red Wall” around Labour’s heartlands, including Stoke Central, Blyth Valley, Heywood and Middleton, Bolton North East and Bury North.

The Labour Party has been written off several times in the past, most notably the early Eighties when it suffered from both the SDP split and the lurch towards left-wing militancy. But it has recovered before and now it can do so again. By backing Starmer, Labour has taken the first step back to power. It is the embattled Tory government whose prospects look bleak.

Leo McKinstry's latest book, Attlee and Churchill, is published by Atlantic