The Department of Transport will today give advisers working for Aer Rianta's trade unions a report detailing the financial future for its three airports once the State company is broken up.

It is understood that the Department will give the document to consultancy Farrell Grant Sparks , which the Government is paying to advise the unions on the financial aspects of Aer Rianta's proposed break-up.

The document contains the projected finances for Cork, Dublin and Shannon airports once they are spun off and trading independently. PricewaterhouseCoopers (PWC) has been working on the report for several months.

The Government has told the unions that they have two weeks to respond to its findings. However, trade union representatives last night reacted angrily to this, arguing that the deadline comes far too quickly for them to consider the report and give a reasonable response.

SIPTU vice-president Mr Brendan Hayes said the union would demand that the Government honour assurances that its members and advisers would be given enough time to study financial and other information relevant to the break-up.

"The union is concerned at the timescale of just two weeks that the Department of Transport has allowed for a response," he said. "The Government's own consultants, PWC, have had much longer to prepare this report and they are building on previous work they carried out for the Department on Aer Rianta last year."

Aer Rianta worker-director Mr Peter Dunne questioned the independence of Farrell Grant Sparks on the basis that the Government was paying it in the first place. "They are being paid by the Department to advise us on the Department's figures. How can we trust that?" he asked.

Mr Owen Wills, general secretary of the Technical, Engineering and Electrical Union (TEEU), said it was totally unreasonable to expect the unions to make an informed assessment of a plan on which PWC had been working for months.

Meanwhile, The Irish Times learned that Aer Rianta last night briefed members nominated to what will be the board of Dublin Airport on the justification for the proposed "Pier D". The Department backed the firm's plan to brief members of the proposed board, including Jefferson Smurfit chief executive Mr Gary McGann and former British Airports Authority chairman Sir Michael Hodgkinson.