Some time ago the law was changed which had previously granted an exemption to Catholic priest from being summoned for jury service. I think the previous situation should be restored because we (and perhaps other clergy too) should never be required in law to be in a situation of passing judgment on others. It also compromises the perception that people should have of us as ministers of the CHurch.
Basically as d escribed above – because the current law compromises our position as religious ministers in many respects.