More than 2,000 gardaí are driving official vehicles without adequate training, figures have revealed.
It has also emerged that the force has the capacity to provide training for only 720 officers a year. Under Garda rules a member of the force must have completed a basic driver training course before being allowed to drive an official car.
However, this can be bypassed under a system known as "chief's permission", whereby the local chief superintendent provides written permission to a garda if the officer does not have the required basic training but does hold a full driving licence.
The system was originally envisaged as a temporary measure to deal with staffing problems in specific stations, but figures released by Minister for Justice Michael McDowell through a Dáil reply last night indicate it is now common practice across the force.
In a reply to the Fine Gael spokesman on justice, Jim O'Keeffe, Mr McDowell said there were 2,013 gardaí driving on chief's permission.
This was made up of 836 officers in the Dublin region, 201 in the southern region, 226 in the east, 252 in the northern region and 366 in the southern region.
In a further reply this week, Mr McDowell said the capacity of the Garda driving school was 720 for training in driving a standard Garda car.
However, he said Garda management had informed him that staffing levels at the driving and training school are being examined, with a view to reducing the number of personnel driving on chief's permission.
Last night Mr O'Keeffe described the figures as "incredible".
He said: "It's very worrying indeed that you have untrained gardaí involved in high-speed pursuits in high-powered cars.
"The individual gardaí can't be blamed. It indicates that Mr McDowell has not provided resources where they're needed, which has put not only the lives of gardaí but the general public in danger."
Last December, The Irish Times revealed that one third of the new recruits to the new Garda traffic corps were also driving on "chief's permission" while only 10 per cent had received the advance driver training that members of the traffic corps have normally had.
The Government is planning to increase the strength of the Garda traffic corps from 574 to 805 by the end of the year and to 1,200 by the end of 2008.
In the late 1990s, three gardaí who were driving on "chief's permission" died in road collisions while driving Garda cars.
Garda representative organisations have also raised the issue of Garda driver training and the quality of Garda cars on a number of occasions in recent years.