AS Westminster packs up for the summer holidays, one of the big parties is grinning and the other is gloomy – but it’s far from clear why.

The happy lot are, of course, the Conservatives, convinced that grateful voters are preparing to flock back to David Cameron in thanks for the fast-improving economy.

Every week at prime minister’s questions, the raucous Tory benches taunt their opponents about a “jobs boom” and the success of Our Long Term Economic Plan.

Opposite them, Labour MPs are suspiciously quiet, struggling for a riposte and worried that their man seems unable to land a telling blow on the cocky Mr Cameron.

Walking around Westminster, it is striking how many Labour MPs fear next May’s General Election cannot be won and may already be lost But what’s this? Two separate pieces of research that suggest the Conservatives are just a little too pleased with themselves. .

The first argues that a crucial group of voters – who are likely to decide the election – are sticking with Ed Miliband, despite his apparent unpopularity.

They are the large numbers of Liberal Democrat supporters who jumped ship soon after the last election, in disgust at Nick Clegg . Looking at polls going back all the way to 2010, the number of Lib Dem voters voting Labour is consistent. They show no sign of going back.

Second, for all the talk that the Conservatives are gaining – because the polls suggesting that are the ones that get publicity – that simply isn’t the case.

In fact, it is Mr Cameron’s party on a slight downward slide and it may be making a mistake in assuming a pre-election bounce.

In fact, according to Southampton University’s Polling Observatory, history suggests there is “unlikely to be a dramatic shift” in the year before polling day.

In the past, a sharp rise in Government popularity may have triggered the election in the first place – rather than vice versa - something now impossible with fixed fiveyear parliaments.

The Observatory concludes: “If the current [Labour] poll lead continues into the autumn, the Conservatives may well need to start worrying. The accuracy of polling as a predictor of the General Election outcome steadily increases as we enter the last six months.”

These academics are predicting a dead heat next year – but, because of voting quirks, that would be easily make Labour the largest party and could even deliver a small majority. So, a little less grinning you Conservatives – and a little less gloomy, Labour.

THE Conservative candidate in City of Durham faces a tough fight – but she’s up for it, judging from her article for the Conservative Home website. Rebecca Coulson wrote: “Anti-Conservative vitriol is heightened up here in County Durham, where the spectre of the late Baroness Thatcher wanders the streets of ex-mining villages. ButI don’t think it’s right for a North-East school leaver to blame their joblessness on a dead 1980s Prime Minister.

“I expect hate mail for the previous paragraph but I really don’t mind. I’d rather say it anyway, and hope it resonates somewhere.”