The Conservative party has often been seen as a well-oiled fighting machine, feared by foes for its ruthless focus on winning and retaining power. During its long history as the country’s most successful political force it has displayed skill at ditching deadweight leaders and for drastic reinvention to reflect changing times. Yet suddenly it appears like a clapped-out contraption, having expended all its energy on a stupid election that has left it spluttering and wheezing while rivals run rings around it.

Much of this is down to that bungled ballot. The party that won, even increasing its vote share, looks like a tragic loser. A hapless prime minister is left hopelessly devalued after throwing away a majority. Her cabinet is in open revolt. Her closest aides have been forced out and her manifesto has been binned. Demoralised backbenchers are plotting to install a replacement but without an obvious successor – and, seeing Labour surge ahead in polls, they fear the impact of a coup. Rumours spread about possible rivals. “Party conference will just be show ponies displaying their colours,” said one dejected cabinet minister.

May could go tomorrow or cling on for five years. Yet right now, almost every step her government takes seems to make matters worse. There was the dismal response to the Grenfell disaster. Then she threw a billion pounds at Northern Ireland to buy parliamentary support from a bunch of bigots, despite the painful pay cap for public-sector workers. Her “fair” offer to European Union citizens living in Britain was filled with holes. And as the clock ticks down on Brexit, jostling ministers have made jibes against each other while pushing rival options, leaving European leaders to look on aghast.

Meanwhile the party that lost the election and remains a significant distance from victory behaves like the winner, its leader hailed a hero and his once mutinous troops declaring sudden loyalty. Such is the reality of politics in a disruptive age. Nothing is certain, experts are discredited, anything can happen. Things are so febrile and the sudden Tory downturn so sharp that Jeremy Corbyn leads opinion polls even when the question is which party leader makes best prime minister. And this fringe figure for decades is feted at Glastonbury like a rock star, crowds chanting his name as he appeals for bridge-building while his close ally accuses fellow politicians of murder.

Jeremy Corbyn is feted at Glastonbury
Jeremy Corbyn is feted at Glastonbury. Photograph: Chris J Ratcliffe/Getty Images

Some might say everything in its right place. Certainly the momentum is now with Labour, thanks to May making her electoral miscalculation of epic proportions. Corbyn still needs to more than double the seats he just gained to win a majority, and deep fissures lurk beneath his party’s surface. But many Tories fear there has been one of those sudden lurches in national mood, like at the end of the 70s. “There are times, perhaps once every 30 years, when there is a sea change in politics,” said the then Labour prime minister Jim Callaghan. “It then does not matter what you say or what you do.”

May saw this shift in attitudes, like others in her party. Her infamous manifesto set out a Conservative vision that challenged “the cult of selfish individualism” and opposed “untrammelled” free markets. (She might note the EU’s strength in tackling corporate misbehaviour with its giant fine on Google). After almost a decade of austerity, many Tory MPs reported back from the doorsteps on growing resistance to spending restraint. Even Oliver Letwin, one of austerity’s key architects and a devout Thatcherite, says ministers must consider tax rises and loosen public spending to appease the public mood.

Government failures and lack of focus on key issues have deepened this lurch to the left; and the latest British Social Attitudes study indicating people are willing to fund higher spending on health, education and disability benefits. Yet at the same time the miserable Tories seem to have given up any fight for free markets, for fiscal responsibility, for smarter running of public services. Such is the mood of despair as they lick their self-inflicted wounds and bicker over Brexit the party has forgotten a key point about politics: there is nothing fixed about the centre ground contested by parties. It moves constantly as it is buffeted by economic forces, social changes and political realities.

This was appreciated by Margaret Thatcher, who argued in her usual forceful style that good leaders move the centre towards them. It also seems to be understood by Corbyn as he drags politics to the left with his remorseless campaigning and hardline views, despite the disturbing conservatism of his outmoded policies. The Labour leader is aided also by a natural tendency of the British electorate to gravitate away from any party in government, as shown by an Essex University study of shifting moods over half a century.

Perhaps it would have been better for Britain if David Cameron had not won outright in 2015, which would have avoided the need to hold that wretched referendum in our divided land. The legacy is a leaderless nation. We are governed by a party that seems to be in office but not in power, which has given up fighting for core beliefs while focused solely on a blurred Brexit. The Tories do not just need a new leader. They need to give their battered machine a makeover, fuelled by fresh ideas to energise younger voters and revitalise the nation. Otherwise, why not just hand the keys of Downing Street to Corbyn now, rather than drag out the misery?