A few months ago the suggestion that Keir Starmer was a lucky politician would have produced bucketfuls of scorn. Luck, of course, is a vital element in any politician’s career, but given events since Starmer took over the reins of his party from his predecessor in April 2020, you would be hard pressed to argue that he enjoyed anything other than the bad sort.

After a positive start, when voters were simply relieved they no longer had to live with the incessant soap opera of Jeremy Corbyn’s leadership, Labour’s poll ratings started to slide again, as voters got to know Starmer and decided, on the whole, that they weren’t particularly impressed with him. Last year’s local elections, which coincided with the Hartlepool by-election, was a nadir for him and his party. Starmer’s subsequent performance during the pandemic didn’t help much: the public seemed content to stick with the devil they knew rather than take a chance with the new boy on the block.

In the last couple of months everything has changed, mostly for reasons that are nothing to do with Starmer or his front bench’s valiant efforts. Labour’s poll lead, however long it lasts, is wholly down to unforced errors by Johnson and his team. But who cares about that? Certainly not the shadow cabinet, who will accept the fruits of victory however they were won.

It may be significant that Johnson’s troubles have largely been caused by his apparent disrespect for anti-Covid rules, including his irresistible urge to attend parties (or work events, depending on the terms of Sue Gray’s final report), and Johnson’s ill-fated attempt to rewrite the rules on House of Commons standards to protect former parliamentary colleague Owen Paterson from censure.

Because even before this winter of discontent for the Conservatives, there were siren voices warning that the Johnson government was already straying too far from any known understanding of the word “conservative”. The pandemic changed the political and economic discourse; measures such as furlough and a range of business support initiatives, including unexpected billions in public support for the railway and bus companies to see them through a period of historically low passenger numbers, transformed the traditional economic arguments that usually define our politics.

It’s certainly true that Labour has been unable, even in these times of staggering levels of public spending, to resist its instinct to demand even more cash from the Treasury. But by the time of the next election, the reliable tactic of pointing the finger at their spendthrift opponents will simply no longer seem a credible tactic for the Conservative Party. Covid has changed much in society but its impact on the political arena goes far beyond arguments over the length of lockdowns or the effectiveness of mask mandates.

How does a “small state” party (in name and reputation, at least, if not in practice) resurrect the successful tactic employed in past elections of putting their opponents on the defensive over their spending plans when they themselves have just presided over the largest short-term increase in public spending since World War II?

It’s when such questions are asked that you begin to see the tactical wisdom of Labour’s enthusiastic support for multiple lockdowns. Their primary concern, as with the government, was public safety. But for Labour, watching from the side lines as the government borrowed on the never-never and wielded the power of the state to control and direct everyone’s lives, the last two years was as much a confirmation of their political philosophy as it was a repudiation of the Conservatives’. Supporting restrictions was, in essence, a win-win.

Unexpectedly, at least for the Right-wing of the Conservative Party, it was not Rishi Sunak’s over-stretched credit card that started to push his party’s fortunes lower in the polls but the personal foibles and judgment of the prime minister. The public seem quite content with a high-spending, high-tax party of government, so long as its leader isn’t seen to be flouting rules on personal behaviour that he himself set.

It’s difficult to see how that can be good news for the Conservative Party, or at least for a Conservative Party that claims it wants to recapture the low tax, small government agenda. Labour, on the other hand, would be only too happy to continue what Johnson and Sunak have begun, and they would at least do it enthusiastically and deliberately, rather than with an apologetic wince every time a few billion was committed or a few per cent added to our tax bills.

It may be hard to believe, but one day the daily revelations about parties at Number 10 during lockdown will cease and the media caravan will move on. At some point, the forces on both sides of the political divide will have to reassemble on the battlefield and decide what they’re actually fighting about. On public spending, the game has already been partly won by Labour. If there is no counter-attack, a new post-Thatcherite consensus will emerge that will be difficult to challenge. And the only casualty will be the Conservative Party.