The exposure of the massive cost of private experts piles further pressure on the Coalition, which is reeling from the spiralling €180 million price of two disastrous computer systems which provoked a political storm this week.
Anger that €70m of the €150m cost of the health service's PPARS payroll system had gone to consultants last night forced Tánaiste Mary Harney to pledge to personally vet such expenditure in future.
The cost of outside expertise is certain to rocket to about the quarter of a billion euro mark as the figures do not include totals for the Departments of Health and Justice.
The scale of the dependence on outside expertise was revealed by Fine Gael finance spokesman Richard Bruton from information collated from parliamentary answers.
Just over €173m was spent on consultants, reports and PR commissions by 13 departments between 1998 and 2005, they showed.
The Environment Department topped the spending league, running up costs of €32m, followed by Finance on €29m.
The Department of Foreign Affairs commissioned the highest number of outside consultancies, reports and PR initiatives 801 followed by Enterprise with 476.
The news came as Ms Harney moved to ease public outrage over the cost of the PPARS scheme.
"In my department I have decided that any consultant employed will have to have ministerial sanction," Ms Harney said.
"There are very good reasons why on occasions you need consultants, when an expertise might not be available in-house in a particular department.
"But consultants have to be the exception and not the norm," she added.
Fine Gael leader Enda Kenny said Ms Harney had missed the point over the PPARS debacle.
"It's not the appointment of consultants that is the issue. It is the management and direction given to those consultants to ensure any project taken on is delivered in a timely and cost-efficient manner," he said.
Concern was also raised this week over the Health Service Executive's FISP financial management system which notched up consultancy costs of €30m.
With his department topping the list of spenders, Environment Minister Noel Dempsey may further regret comments on the PPARS system this week, when he said the level of misspent money was "relatively very, very small".