As I understand it, organic must be GM free but GM free feed isn't organic. There seems to be three levels - organic (the most expensive), GM / antibiotic free such as Farmgate, A&P Smallholder Range, Marriages (I think) (at middle cost), then the cheapest which will have GM ingredients, possibly antibiotic growth promoters etc.
In a perfect world, I woudl like to use UK grown, cheap, organic feed. But I gain nothing in sales because I can't sell my pork or eggs as organic and if the grain and soya comes from abroad, then maybe I'd be better with UK sourced GM free. I won't go below GM free standard.
I have the same dilemma about organic Dutch bacon and British bacon of dubious animal welfare standards.