Opposition TDs yesterday accused the Minister for Transport, Mr Brennan, of using incomplete financial information to justify his controversial plan to break up State airports' operator Aer Rianta.

Speaking at a meeting of the Dáil Select Committee on Transport, Labour TD Ms Róisín Shortall said that a review carried out for Aer Rianta's trade unions by accountants Farrell Grant Sparks (FGS) found that a working paper completed for the Government by PricewaterhouseCoopers (PwC) was not meant to examine the implications of breaking up the company.

She told the meeting that the PwC working papers were not complete. "But that was the totality of the financial information the Minister relied on to the make the case to Government," Ms Shortall said.

She was speaking on an amendment to the State Airports Bill, 2004, which will pave the way for the break up of Aer Rianta into three separate airport authorities - Dublin, Cork and Shannon.

Ms Shortall and Fine Gael TD Mr Denis Naughten proposed a number of amendments designed to force the Minister to publish a business case for the proposal before going ahead with it.

Mr Naughten warned that it was vital that the Oireachtas was first given the financial justification for the plan before passing the law. "The Minister is asking us to pass the legislation on the promise that we will get to see the business case and financial plans at some later date," he said.

In response, Mr Brennan pointed out that, once the legislation was passed, the new airport authorities would have to draw up business plans, which would in turn have to get the Dáil's approval, before they could be spun off as independent entities.