Here's your source.
The professional pundits are probably right. This is a backlash of sorts against UKIP. The greater their presence is felt, the more their backwardness is plastered all over the media the stiffer the resistance to their blandishments becomes.
But that is not all. Weirdly, I think a little bit of anti-politics sentiment is bound up with this. Consider it, every time you turn on the news or open a paper, politics stories always seem to be blah, blah, Europe, blah, blah, referendum, blah, blah more Europe. It's really bloody dull. The problem is as the Tories have stupidly decided to try and out-UKIP UKIP by offering a referendum on a renegotiated relationship with the EU - a series of negotiations Dave will flunk in spectacular style - the knee jerk rejection and reaction to this interminably boring, alienating and remote politics finds itself expressed in maintaining Britain's membership. Perhaps its just as well Labour and the LibDems aren't making a big deal about EU support in the run up to next year. Unlike the Tories and UKIP, they are aware it's a priority for approximately seven per cent of voters.
Is this existential crisis time for UKIP? You know how the story goes. In fact, the Tories are banking on it. The blue team are returned next year, Dave successfully renegotiates EU membership, the referendum happens, a yes vote wins out and UKIP withers away to nothing. All those voters dutifully return back to the Conservatives and they go on to win a thumping third term in 2020. Sadly for Dave and everyone pinning their hope to this scenario, no. The salience of UKIP is expressive of and capitalises on long-term social trends that have, for a section of the population, made living in Britain feel as if it is a scary, insecure and unfamiliar place. To think an EU referendum followed by a yes vote is going to kill the kippers stone dead is to indulge Westminster determinism of the very worst sort. They are a sociological phenomenon and as such only long range policies that ease insecurity, such as building more affordable homes, tackling low pay and job insecurity, and doing something about the mountains of private household debt piling up will sort them out. After all, whatever happened to the SNP after the Scottish referendum?