Reaction:Opposition parties last night paid warm tributes to Mr Justice Flood on his retirement but warned that the planning corruption investigation now faced considerable uncertainty.
Fine Gael leader, Mr Enda Kenny, called on the Taoiseach to tell the Dáil next week how the resignation would affect the work done so far by the tribunal; the issue of costs, particularly in relation to those who have may have hindered or obstructed its work; future planned modules of the tribunal; and the sequence of events this week which have led to Mr Justice Feargus Flood's resignation.
He asked why Mr Justice Flood, who had initially wanted to remain on as an ordinary tribunal member, had now decided to resign altogether.
"The Taoiseach's comments today, that the resignation will not act as an impediment to dealing with the costs issue, is at odds with remarks earlier this week on the same issue. Which is it to be?
"Will the taxpayer end up paying the costs of the tribunal or not?"
Labour's environment spokes- man, Mr Eamon Gilmore, said Mr Justice Flood's resignation had pushed the tribunal into "difficult and uncharted territory, particularly over the issue of costs.
"In this context it is truly shocking that the public may, if the issue is not handled properly, end up being saddled with the costs of all parties before the tribunal, including the outrageous amount submitted by the former Fianna Fáil minister Mr Ray Burke, for almost €10.5 million, amounting to almost 50 per cent of all notified costs."
He said every step should be taken to ensure this "unthinkable scenario" did not develop. The Green Party leader, Mr Trevor Sargent, said he was surprised at the sudden resignation, saying this was "a cause for serious concern".
He called on the Taoiseach to make a full statement outlining the circumstances behind the sudden resignation.
The Sinn Féin Dáil leader, Mr Caoimhghín Ó Caoláin, called on the Government to introduce legislation to regulate the fees of legal teams at tribunals as well as its planned Bill in the autumn to try to ensure challenges to tribunal rulings on costs won't succeed.
However, he said the Government plan to legislate to allow private inquiries instead of tribunals should be rejected.
"While Mr McDowell claims this would reduce costs it would be at the expense of transparency," he said.