Blackadder...for your information :::
http://en.wikipedia.org/wiki/Electoral_Calculus
As you can see, EC is not a Polling organisation and does not commission Polls of its own. To quote from its own website :::
Electoral Calculus predicts the next British General Election result using scientific analysis of opinion polls and electoral geography.
Have a good look at the site, not just its headline predictions. It contains very in-depth analysis of every constituency in the country. If I look at my own, Gower in Wales, I can see exactly what the voting was in every ward. You can do the same with your own.
Its a very useful site, with masses of details and information, and is worth a good perusal, if you can only get past your own prejudices !