Fifteen weeks until the election and in what might be one of the last covert moves before the parties stop pretending they're not campaigning, Cameron got stuck into opponents with a sneaky piece of innocent-faced chicanery, aimed at both putting clear water between himself and Ukip, and zapping Labour on an increasingly important issue.

Health Minister Jane Ellison announced Wednesday night that the government would give MPs a vote before the May general election on regulations compelling tobacco firms to display completely plain cigarette packaging. And this before the consultation exercise on the packaging proposals has even ended. So what's the sudden rush to move this issue forward?

With the ongoing crisis in A&E care the issue of the health service has the loudest cough in the room and that cough, according to MORI, ComRes and YouGov polls, is only getting louder. Cameron's strategists could hardly not have heard it, even without the polls of billionaire Tory peer Lord Ashcroft of Belize, whose data puts Labour 16 points ahead of the Tories on the issue of health. All of which may have led to the the following conversation between Tory advisors, who we're going to call Lambert and Butler:

L: It's looking pretty ropey on the health front. What's to do? We need a quick win.
B: Er. Health. Yeah. Exercise. 2012. Is there any Legacy left?
L: Baron Coe has taken all the Legacy.
B: Car crashes, they're unhealthy. Let's stop them. Let's be seen to be stopping them.
L: Hmmm.
B: Bears, they can maul a man to death, we could hurt some bears.
L: I've got it... Fags!

So fags it was. And by crow-barring a free vote on being seen to be against fags into proceedings, the Tories hope to be given a shiny tick with which to claw back a bit of the health initiative from Labour. But just as importantly, this vote plays to the Tories' other vulnerable flank, because once more they get to show the voters the swivel in the eyes of Ukip.

It's no secret that Ukip leader Nigel Farage loves a tab, being a devotee of the cut skag of the fag world, Rothmans. And it's no secret too that he loves a bit of horse-faced, tub-thumping libertarian rhetoric, so with this in mind what response might the Tories have expected from Rothmans man, Nige? That's right, a batshit one.

And batshit Nige has taken the bait like the dimmest of crocs. 'Plain packaging,' he says, 'is an appalling intrusion into consumer choice and the operation of the free market.'

An 'appalling intrusion'? Really? Not having a fag maker's brand on a box is an appalling intrusion? Not really Nige. It's not even a mild inconvenience. Not even for the fag firms apparently, who duplicitiously state that shiny fag boxes have no effect on making people smoke, (whilst at the same time lobbying desperately hard to keep their shiny boxes shiny).

So suddenly Ukip have forgotten they're supposed to be on their best pre-election behaviour, giving us confidence they're not grudge-bearing anachronistic cranks, dribbling fearfully about bongo bongo land and klepto Romanians camping in the garden. But with one threat to Nigel's beloved Rothmans  logo the facade has melted and they're belting about declaring themselves pro-pleurisy, pro-emphysema, and suddenly having shiny boxes of fags is one in the eye for the nanny state, and giving yourself chronic obstructive pulmonary disease is a new human right. Or it would be if Ukip believed in such things.