“Extraordinary levels of corporation tax” are becoming so heavily baked into Ireland’s budgetary policy that the Irish Fiscal Advisory Council (Ifac) wants the Oireachtas to step in and stop the Government from spending it all. The budget watchdog’s warning, now a staple of the budget season, takes a new twist not only because of its call to enshrine fiscal rules into legislation, but also because it is based on new medium-term fiscal plans from the Government to the end of this decade. The publication of Ifac’s Fiscal Assessment Report this Wednesday caps off a week-long trickle of data and analysis,…