Indeed. I would much prefer there to be no exception, and imports only permitted when they comply with uk legislation. And I would prefer that to be the case in many other areas. If we insist on a high level of safety at work, why should we import goods made in an environment that is less well...
It's not whether it is Halal or Kosher that should be the label. All you need is a label saying "Slaughtered under the religious exemption - halal". Then those who think every one should obey the same laws, or believe that pre-stunning is a compassionate path to slaughter could make the choice...