Rochester by-election: UKIP did less well than expected (and Labour suffered a malfunction)

The Conservatives can expect to win the seat back at the general election next year

Mark Reckless, who defected to UKIP, held his seat in yesterday's by-election with a majority of 7 percentage points. A decisive victory, but not enough to ensure that UKIP keeps the seat at the general election.

The figures:

UKIP 42% (didn't stand in 2010)

Conservative 35% (-14)

Labour 17% (-12)

Green 4% (+3)

Lib Dem 1% (-15)

The most recent opinion poll in the constituency, by Lord Ashcroft on 7-10 November, put UKIP ahead by 12 points: last night UKIP came in 2 points lower and the Tory 3 points higher.

That suggests that the polls overstated UKIP support (and understated Tory support), or that the Tory campaign gained ground in the last 10 days, or both. There have been four polls in the constituency – a record: it used to be unusual to have any polls at all – and they all overstated UKIP's lead:

Survation, 1-3 Oct: 9 points

ComRes, 17-20 Oct: 13 points

Survation, 27-28 Oct: 15 points

Ashcroft. 7-10 Nov: 12 points

That last poll found that, by a 1-point margin, voters who expressed a view said they would vote Tory over UKIP when it came to the general election. Last night's result suggests that it will be hard for Reckless to hold the seat.

As for the other parties, the Greens were the only other one to add to their vote share from the last election. The Liberal Democrats can say that at least they came in the top five, beating off a spirited challenge from the Official Monster Raving Loony Party.

And Labour, although it lost slightly less of its 2010 share of the vote, managed a last-minute embarrassment of epic tragi-comedy.

Emily Thornberry, the shadow Attorney General, tweeted a photograph of a house draped with St George flags, with a pillared porch and a white van parked outside. "Image from Rochester" were her only innocently meaningful words.

________

This confirmed (a) how sound David Cameron's judgement had been about the dangers of politicians using Twitter, and (b) that Twitter is now a picture-led medium.

It seemed trivial, but it wasn't. Class condescension is one thing that Labour cannot afford. Thornberry affected surprise when journalists started phoning her to ask her what she thought of being called a snob. "I just thought it was extraordinary," she said. "I had never seen a house like that." In which case, the streets of Islington are an even more rarified and precious place than any of us had realised.

Ed Miliband and Thornberry spoke (a spokesman said the Labour leader had never been angrier, which seemed either odd or an exaggeration) and she apologised.

Later, they spoke again. By then the story was going to be on the front page of The Sun, and she announced her resignation "from the shadow cabinet", although she was not actually a member of it. (She was entitled to attend, just as the real Attorney General is entitled to attend the real Cabinet, but is not a Cabinet minister.) Labour's spokespeople could have pointed this out, which might have helped diminish the resignation somewhat, but they didn't seem to know, and anyway her departure is important: she had been close to Miliband – he chose her as his PPS (ministerial aide) when he was Energy Secretary.

It is extraordinary that, although UKIP's victory was significant, the image from a single tweet could make a longer lasting impression on the voters' minds at the general election.