We never agreed that as part of common market. We had referendums including on entry to common market. Over and over we were told that common market did not mean common tax policy, and that we'd have a veto in the council on any attempt to bring common tax policy in. The people of Ireland are sovereign in Ireland; it's not acceptable to tell us we must abide by something we did not agree to or we must leave. Tax policy has long been a national issue and this is an attempt at harmonisation.