When an election looks hard to win, MPs sometimes seek solace in the myth that it might not, after all, be so bad to lose. Before 2010, the exhausted Labour ranks were infected with this virus, whose symptom is a delusional belief in the restorative properties of a spell in opposition. Now, the same malady is breaking out on the Conservative side.

It is, for the time being, confined to a kernel of 30 or 40 backbenchers. They have drunk themselves morose on a cocktail of resentments – call it ambition on the rocks – that is one part irritation with David Cameron’s snooty manner and one part injured pride at missed promotions, stirred together with a fizzy mixer of ideological betrayal. The irreconcilables would take pleasure in seeing the Prime Minister’s smooth features crumpled by election-night disappointment.

Letting Cameron take a general election hit is also the clearest route to replacing him. A Ukip surge in the European Parliament elections next May might provoke a spasm of plotting but most Tories expect the incumbent leader to continue until 2015. Increasing numbers even think he can win.

But a minority also wants Cameron to fail, so his metropolitan “modernising” clique can be discredited for good. From the ashes of defeat can then rise an ideologically purer party, dedicated to quitting the European Union, cutting taxes, breaking up state-run services and not playing lickspittle to the Liberal Democrats. Besides, carrying on under Cameron would become impossible as soon as he started campaigning for Britain to stay yoked to Brussels.

This attitude is not quite the same as defeatism, which is the fatalistic anticipation of loss. It is defeatophilia – a sadomasochistic faith in the purgative benefits of electoral spanking. The obvious rebuttal is that unity around a sharpened doctrine won’t be much use in opposition but the Tory defeatophiles have an answer. Labour’s inability to govern in austere times, they say, must be exposed. Let Ed Miliband flounder before the challenge of cutting budgets with his trade union paymasters in uproar. Only after a catastrophic single term of unstable Labour (or Lib-Lab) rule will the national appetite be whetted for authentic Conservatism; bring on another winter of discontent to augur the second coming of Thatcherism.

This mania, according to sensible Tories defending marginal constituencies, is an affliction among colleagues with unassailable majorities. (“It’s the sort of stupid thinking you get in a rock-solid seat,” one Cameron loyalist tells me.) Partly, it is provoked by Ukip activity in local associations, which has exposed complacent lifers to unfamiliar and unnerving volumes of dissent.

It isn’t just Tories who look beyond the next election and foresee Labour struggling to govern. There are opposition MPs who expect to win while struggling to relish the prospect. Ed Balls’s recent declaration of austere intent – pledging to spend within the same frugal framework as the coalition – was met with relative equanimity among Labour MPs. Most recognised that such a gesture was necessary. Some thought it overdue. When Balls’s plans were revealed to the shadow cabinet, the dominant mood in the room, I am told, was relief. There is a strong feeling on the front benches that the party is now better equipped to talk about what a Labour government would do in the future, instead of harping on about what the coalition should have done differently.

Inevitably, angry voices on the left decry Balls’s new position as surrender. There are also Labour hawks who fret that Balls and Miliband have only signed up to Budget discipline in theory and won’t level with people about how tough things will get in practice – what one shadow minister describes as “showing the voters a dead puppy”.

Meanwhile, just as Labour turns a tentative gaze towards the Budget gorgon, the coalition is recoiling in horror. The Spending Review of October 2010 was a parade of ceremonial butchery, as zealous new ministers offered up their departments to George Osborne’s sacrificial axe. For the review announced on 26 June, every penny of the expected £11.5bn in cuts has had to be prised from clenched fists.

It is getting harder for Tories to paint squeamishness about cuts as a lefty affliction. Ministers with solid right-wing credentials – Theresa May in the Home Office, for example, or Philip Hammond at the Ministry of Defence – are bolshie in defence of their budgets. Austerity fatigue is well advanced in both Labour and Tory councils.

According to the Institute for Fiscal Studies, sticking to the current trajectory for deficit reduction will result in further cuts of £23bn in 2016-2018 – a squeeze it describes as “almost without historical or international precedent”. That strips some of the lustre from a 2015 election victory. Conservatives boast that they have the will to inflict pain, while Labour shrinks from the task. Labour insists it has discipline and, unlike the Tories, can do the job with compassion.

There is also a faction in the Conservative ranks that expects to watch Labour scrape into power without a mandate to do nasty things and then fail in ignominy. There are Labour MPs who fear the same scenario. In public, politicians always declare confidence and determination to win. Yet there is a stage that comes before resignation to defeat, which is finding comfort in the thought that your enemy will choke on victory.