The post you are reporting:
Keith, Labour is currently on a downward slide.
Also, past opinion polls were not correct.
ConRes have changed their way of polling.
When asking people who they'd vote, they had been assigning to the three main parties (Tories, Labour and Libs) any unsure preference, such as a 5 out of 10 chance of voting for one of them, or 6 out of 10 chance and so on.
But they would only assign to the smaller parties a 10 out of 10 chance.
Now ComRes have decided to treat all parties equally.
The result was seen in their latest opinion poll the other day, done for the Mirror, in which the Libs got 8%, UKIP 14%, and Labour 37%.
The question is, how does YouGov conduct its polling methods, do they treat all parties in the same way?
In fact, there have been many questions recently as to why YouGov's polls are always low for UKIP and other smaller parties, and extremely high for Labour.
So, depending on how polls are conducted, people might think that only parties with a large rating are doing well, and consequently also vote for them, so as not to give a "wasted vote" .
If the polls are not calculated fairly in the first place, they can influence people's decision on how and whom to vote for.
So if Labour has been a beneficiary of this sort of poll conduct, it might explain a few things.