gaelicsheep
A few things here in response to the OP. I'm fairly repulsed by this, we ate these very burgers last night. However I'm not repulsed by the concept of horse meat per se, albeit that it's not something we tend to eat in our culture. What repulses me is that I bought these on the basis of them containing 63% percent beef - a higher percentage than the more expensive ones as it happens - and not too many nasty "additives", but god only knows what they actually contain. There could be anything in there, far worse than horse meat.
I don't like cheap processed food or the concept of it. We are on a severe budget at the moment which is why I bought it just this once. But to my mind if the meat is from a reasonably high welfare source - ie NOT chicken from Thailand or pork from Denmark, for example - then I am not too bothered by the concept of the processed meat itself. I have assumed Irish beef is reasonably high welfare - if I'm wrong on that score then I hold my hands up, but as a general rule I only buy British or Irish anything.
What you and most consumers don't realise is that the meat you're buying can come from anywhere in the EU, unless it's specifically labelled as British or Irish, and you have to look hard to check that it's British. Suppliers are entitled to source their meat from anywhere in the EU, and the quality of the inspection is dire outside the UK.
This is, of course, a consequence of agriculture being run by Brussels, a factor I hope you'll consider next time you vote. 
You can look for the red tractor on the pack, which signifies a British product.