Labour leader Jeremy Corbyn. Nick Ansell/PA Wire/Press Association Images. All rights reserved.

As political strategies go, David Cameron’s plan to hold a referendum on the UK’s membership of the European Union is almost perfect – apart from the fact that it is inherently flawed. He forgot to account for the hitherto unimaginable risk that the leader of the Labour party would decide not to campaign for 'Bremain'. Ultimately, however, the damage to Labour will be just as significant.

It is of course a bit of a stretch to say that the decision to defer to the one-off wisdom of the British people with an irreversible plebiscite represents a well-considered plan on the part of the Conservative leadership. It was more or less forced on Cameron by the Conservatives’ inexplicably rabid backbenchers in the context of his failure to win a majority in 2010, a dynamic that has also compelled him to reluctantly include some of those most afflicted by Europhobia in his cabinet.

Clearly, as Iain Duncan Smith’s resignation proves, the Brexiteers’ empowerment does not eliminate their propensity to self-destruct. It is ridiculous to claim, as some have, that Smith’s resignation had nothing to do with Brexit. Iain Duncan Smith is a person with a great many things clattering around in his brain at any given moment, and Brexit is clearly one of the big ones.

So it wasn’t a rational decision: it might have generated a few negative headlines for Cameron and particularly George Osborne, but ultimately Smith’s attempt to align himself with anti-austerity sentiment is an invitation to ridicule, and undermines his credibility on every issue about which he may wish to opine.

Nevertheless, while Cameron and Osborne might not have chosen to stage a referendum, they will have quickly understood the upsides. Holding a referendum on the EU would, in normal circumstances, strongly benefit the centrist wing of the Conservative party that they claim as their own. But the ascendance of Jeremy Corbyn renders the moment anything but normal.

There are potentially four main upsides for Cameron and Osborne. Firstly, as excruciating as the referendum campaign was always going to be, a few months ago they could quite reasonably have expected to have won it fairly comfortably. Brits might love a loser, but we vote for winners.

Secondly, and as alluded to above, the referendum flushes out of the Tory ranks some of those most consumed by Europhobia, like Duncan Smith (he would have been pushed on 24th June had he not already jumped). This applies also to Cameron’s friend Michael Gove.

Gove is seemingly disliked by large parts of the electorate, which is why he was half-sacked in 2014; the only reason Cameron has allowed the notion that he is deeply hurt by Gove’s decision to join the out campaign to filter out is because it allows Gove to be painted as disloyal and untrustworthy. Think Michael Fallon and the ‘stabbed his brother in the back’ line from the 2015 election campaign. How unfortunate that Gove’s wife Sarah Vine appears to genuinely believe that Cameron tried desperately to change her husband’s mind. The game is the game, Sarah.

The referendum has also, thirdly, explicitly flushed out Boris Johnson’s unique rabidity, that is, his flaming ambition. Johnson is no more Europhobic than most (something else which is lost on Vine), but he knows deep down that he is admired by few on the Tory benches, and that aligning himself with the Brexiteers was his only realistic way of securing their nomination in the next leadership contest. Boris is also a winner. The chance to corner him into what would normally have been a losing position is one that Cameron and Osborne will have eagerly embraced. Boris would be on the ballot, but weakened.

The fourth and most important reason is that campaigning successfully, alongside the Labour party, in support of a pro-EU campaign is a guaranteed path to the political centre. It would have represented a watershed moment in the Cameron-Osborne hegemonic strategy, enabling the Conservatives to demonstrate their centrist and safe-pair-of-hands credentials to an electorate which, they believe, is quite happy with the way things are.

The message – insincere, but effective – would have been that there is nothing to fear from continuing Tory rule. We’re the same as Labour on all the big issues, so the argument goes, and a bit better at managing the economy. It is in fact a trademark Osborne move: undermine the Labour opposition by borrowing all of their distinguishing ideas, while getting on with the business of implementing our own agenda without scrutiny (think ‘national living wage’).

That Cameron and Osborne probably do believe the UK is better off in the EU is almost incidental. Above all, they believe the UK is better off, whether in or out, when governed by David Cameron and George Osborne.

The problem is that this upside depends on Labour playing along. At the most basic level, Labour voters are needed if the referendum is to be won. More importantly, only if Labour is situated at the sensible centre with a pro-EU position are Cameron and Osborne able to present their own perspective as classic consensus politics.

But this is not where Labour is at all. Most of the shadow cabinet might be explicitly pro-EU, but Jeremy Corbyn and John McDonnell are instinctively anti, subscribing to the Bennite view of the EU as a ‘capitalist club’. Corbyn is nominally campaigning for 'Bremain', but not in a way that anybody only half-interested in politics (that is, almost everybody) might actually notice.

Labour voters are broadly in favour of EU membership, but they are not going to turn out in their millions to proclaim so on 23rd June without a little encouragement from Labour’s most (or only) high-profile figure.

Yet even if the inners scrape a win, Cameron and Osborne’s strategy – upon which the latter’s ascension to the former’s job probably depends – has already been significantly undermined. They are left leading a campaign which is increasingly seen as the establishment perspective, while the anti-establishment space is perversely filled by the Brexiteers of UKIP and the extreme Tory right.

To some extent, Cameron and Osborne do have only themselves to blame. Such is their detachment from everyday life on this island, they probably thought it was inconceivable that Labour members and supporters might be so disgusted with austerity that that they would select someone who is, at best, agnostic on EU membership as their leader. Furthermore, their unwillingness to compromise in any substantive way on austerity shows how shallow their centrism is.

But this does not mean that Corbyn et al. should be let off the hook. Labour should be fighting hard for the UK to stay in the EU, even if it benefits Cameron and Osborne in the short-term, because the only viable alternative scenario sees the UK run by right-wing zealots for whom Brexit is only the tip of the reactionary iceberg – or at least by a man now permanently beholden to this group.

Moreover, a savvier Labour leader would surely have recognised that Cameron and Osborne’s 'Bremain' strategy is evidence of their weakness, not their strength. They are hegemonic wannabes. Cameron and Osborne are unable to build a sustainable electoral coalition around their real agenda, because in our stratified society and dysfunctional economy, so few derive any benefit from that austerity agenda.

Labour could over time have exploited this weakness. Whichever way the result goes, the Conservatives will be torn apart by the referendum. By owning the centre, Labour could, in return for ideological succour, have forced concessions from Cameron and Osborne on austerity. Only a pro-EU position is consistent to the idea that we should be worrying most about how to change Westminster and Whitehall; anything else is just helping the Brexiteers’ misdirection campaign. Corbyn will never have a better chance than this to put Labour back at the heart of our national conversation – but it may already have passed.