“A funeral”, “a wake”, “awful”, “dead”. These are some of the words used by attendees to describe Labour’s annual conference last week. That is Labour, the party which barring a miracle will sweep to power at next year’s general election and see its leader, Ed Miliband, become Prime Minister.

Contrast that language with “upbeat”, “happy” and “punchy”, some of the words used by delegates gauging the tone at Conservative Party conference in Birmingham this week. A party which, exempt that same miracle, is highly likely to be consigned to defeat in eight months’ time.

The Prime Minister was on combative form on Sunday night at a party held for MPs, journalists and high profile party members at the top of the poshest hotel in England’s second city. David Cameron delighted his audience by dismissing Labour as a “complete shower”, also condemning turncoat UKIP defector Mark Reckless with a series of stinging comments vowing to regain his seat for the Tories.

Tory supporters purred after their leader’s speech that they had really seen him on such good form, and that if he were to repeat that effort in his main speech in the conference hall tomorrow he could count this year’s proceedings as a success.

There have been one or two positives for the Tories this week. Yesterday, the Chancellor George Osborne delivered a rallying cry to the party’s base, which many see as having been deserted by the current leadership, pledging to scrap the so-called ‘death tax’ on pension pots. Later that afternoon, Work and Pensions Secretary Iain Duncan Smith said the Tories would trial a plan for pre-paid benefits cards preventing welfare recipients from spending taxpayers’ money on alcohol. Two sound conservative policies that understandably went down well among the party’s grassroots.

But is that really reason for the Tories to be cheerful? Over the weekend they lost a minister to a sex scandal, and a backbench MP to UKIP. Rumours are swirling around conference that Nigel Farage has convinced another Tory to defect to his party.

Given the uncharacteristically impressive secrecy with which UKIP managed to keep the Douglas Carswell and Mark Reckless defections, it is hardly an impossibility that a third could jump ship an hour before Cameron’s big speech. Downing Street strategists will be planning for a worst-case-scenario situation.

And why was Labour so downbeat? Why was there such anonymous – and on the record – criticism of Miliband who, for all his personal and political failings, is the clear favourite to be sitting in Number 10 next May?

Labour don’t know how good they’ve got it: ahead in the polls, enjoying the advantage of a skewed electoral system and lucky enough to be fighting a party which has consistently failed to inspire the swing voters necessary to secure a majority.

Why, conversely, are the Tories so chipper, considering they are by all accounts set to be booted from office in just a few months’ time? You wouldn’t know that from speaking to MPs and members in Birmingham.

It is almost as if the idea of a Miliband government, however inevitable, is so terrible and unthinkable that the Tory mindset is refusing to acknowledge its potential existence. Barring a miracle, delegates at this year’s conference will be in for a surprise next May.