DUBLIN (Reuters) - The Irish government was on the verge of collapse on Thursday after the party whose votes Prime Minister Leo Varadkar depends on to pass legislation appeared set to break the terms of a  confidence and supply  deal. The opposition Fianna Fail party said it would put a motion of no confidence in Deputy Prime Minister Frances Fitzgerald on Tuesday, a move that would breach the deal it agreed to support Varadkar s Fine Gael government in key votes for three years.  Fianna Fail indicated it might withdraw the motion if Fitzgerald resigned, but Foreign Minister Simon Coveney told state broadcaster RTE that Fitzgerald would not resign. The crisis comes weeks ahead of a European Union summit in which the Irish government has an effective veto on whether Britain s talks on leaving the bloc progress as it determines if EU concerns about the future of the Irish border have been met. 