Well Dave I think after the last referendum a sensible person would be very wary of placing too much faith in any sort of poll involving Joe Public. There is no way of cross checking the true feelings of the person being polled. Are they honest, mischievous, or just trying to throw a spanner in the works? I could be any one of those, depending upon the question being asked.
But in the case of the above link the conclusions are hardly controversial and most people would be in broad agreement with the result. One can hardly regard the guardian as being off way to the right of Attila the Hun.