I’d have more sympathy for Labour’s outrage about this leaflet if they DIDNT DO THE DAMN SAME THING THEMSELVES!!!
My wild guess is, David Cameron will announce a specific date for the UK's EU referendum, and that date will be roughly a year from now. The result of that move will be to tip help tip Labour out of the seat (see the graphic showing one of UKIP's campaign posters), regardless of whether it winds up UKIP or Conservative. That avoids the head-on collision the Tories would suffer if he announced new restrictions on immigration. [reprised comment]