Totalla agree about the labelling- we all should be able to know what we are buying and make the choice. Absolutely.
Your point about the law is not as clear as all that, really. The Law states that stunning must be done previous to the kill. Some forms of stunning are totally un-acceptable according to the Koran, but electrical stunning is not.
So why not compromise- not on the Law, but on the way to apply it- in order to find a solution that will be acceptable, and show willing and better understanding. What is wrong with compromising- if the compromise agrees with the law of the country. A refusal to compromise, WITHIN the law, is not helpful and will, not surprisingly, be seen as just being controversial in a way that coud be interpreted as racist and unfair.
I would never compromise, on, say, genital mutilation or enforced marriage - but in this case, a good and lawful compromise IS AVAILABLE, so why not push for that option, rather than a ban and insist on forms of stunning which are not acceptable according to the Islamic faith. If there was no solution which could satisfy all- it would be a different kettle of fish. But there is - a good solution- legal and also acceptable to the Koran.