Perhaps the best thing that could have happened to the Labour Party in the by-elections in two of its traditionally held seats is that it should have lost them both badly, with fewer alibis and consolations falling to hand. Only a true calamity might have convinced the party's grassroots that Jeremy Corbyn's leadership and a political strategy based on the NHS threaten the party's very existence.

Instead we have, as with previously lame electoral showings, a main opposition party too weak to have any hope of replacing the Conservatives in 2020, but still robust enough not to be forced into the sort of radical change it needs – perhaps before it is too late. Like its leader on his beloved allotment, Labour will continue to potter around the place attending to its routine chores, hoping for the best and for the sun to come out, rather than actually doing something to make the political weather.

And of course the Labour leadership and their Momentum praetorian guard can always blame the legacy of Blair/Brown/Miliband; the “failed coup”; Owen Smith; the recent interventions by Mr Blair and Lord Mandelson on the EU; and any number of other handy scapegoats for their miserable showing.

The fact that Labour may be heading for its worst showing at a general election in a century seems plain to anyone examining the trends in the polling – which remain dismal for Labour – in the slow and confused pace of the party’s policy development, and, indeed, its showing in local elections and by-elections. The hope that the remarkable insurgency that delivered Mr Corbyn his party’s leadership twice over will spread into a sort of Trump-like national phenomenon looks forlorn. But those grassroots activists who have invested so much emotional capital in Mr Corbyn show no sign of abandoning their faith – and it is sometimes a near religious devotion.

It is perfectly fair, too, to the extent that Mr Corbyn came to power at the head of a genuine democratic enthusiasm for a new kind of personality at the helm, a movement aimed at changing society. It just doesn’t happen to be one that appeals much to the British public more widely. Moreover, there were enough crumbs of comfort in the results to allow Mr Corbyn and his support base to discount the critics.

As things stand, the utter incompetence of the Ukip challenge in Stoke has allowed Labour's lacklustre candidate to waffle on about a victory of hope over hate, and Labour nationally can argue that they saw off Ukip – a welcome development, but not sufficient to place Mr Corbyn in No 10.

In Copeland, the plainly overriding importance of the nuclear power industry offers Labour spin doctors – they still exist – the excuse that Mr Corbyn's long-term principled opposition to all things atomic did for Labour in this special constituency. No matter that the NHS issue was as salient there as anywhere, and as ever, the voters looked to their wallets first. Maybe some even bought the Conservative line that you need a strong economy to pay for a strong NHS – just as they did during Labour’s last time in the wilderness in the 1980s.

In Stoke and Copeland Labour undoubted suffered a humiliation: bad enough to demoralise them but, crucially, not grave enough to provoke the radical change in direction Labour desperately requires to become politically relevant again.

All of which leaves the Conservatives in a strangely commanding position. The swing to them in Copeland was an impressive one, and their near second place in Stoke, a mere 79 votes behind the would-be insurgent Paul Nuttall, must have been almost as gratifying. Ukip's leader should be ashamed of both his own behaviour and the eccentric claims he made about his personal CV, and the wider political failure to take Ukip forward. After it won the EU referendum it is not clear to voters what, precisely, Ukip is for. The answer was supposed to be that, Trump-like, it would lead a political peasants’ revolt against the mythical “liberal elite” and storm the citadels of power. Nigel Farage last year talked excitedly in such terms.

Stoke would have been a fine base for such a campaign. The city, as has often been noted, was a dream seat for the ’kippers; the highest Leave vote in any city and the lowest turnout in any UK constituency in the last general election. No other place represents the sort of disillusion and neglect by Westminster and Whitehall that Ukip is supposed to thrive on. Well, whatever potential there might have been, Mr Nuttall blew it, his personal humiliation exceeding Mr Corbyn’s. Ukip have had their thunder stolen by the sometimes stridently anti-European Conservatives, and such threat as they ever posed to Theresa May’s party has receded decisively.

Ms May, then, can scarcely believe her luck. With only the feeblest recovery in Liberal Democrat fortunes and the Greens being outflanked by the Corbynistas, the opposition to her across Britain, outside Scotland, is hopelessly, kaleidoscopically divided, and with leaders who have all been found wanting by the electors. Only Nicola Sturgeon can rival Ms May for voter appeal, yet even in Scotland the Conservatives, under the combative Ruth Davidson, are enjoying a renaissance.

In a first-past-the-post system with the anti-Government vote split between Labour, Ukip, the Liberal Democrats, and the Greens, plus the SNP and Plaid Cymru, the Conservatives wouldn’t need much of a vote in 2020 to govern with a comfortable majority. Indeed, Labour could fall to as little as 150 parliamentary seats, which could gift Ms May Tory majorities in the Commons not seen since Margaret Thatcher’s famous victories in the 1980s – but beyond a certain level the political territory is truly uncharted.