Fine Gael has called for a delay in the implementation of the penalty points system for motorists, which is due to come into force on Thursday.
Party spokesman Denis Naughten said there are still many question marks hanging over the system, which was described by the Garda Representative Association last night as ham-fisted, bureaucratic and unworkable.
The GRA also said that its members have not even been briefed on the scheme, which will be operated manually for an initial period until a computerised version is established.
Transport Minister Seamus Brennan said he has received assurances from senior Gardai that the system will be implemented from Thursday, despite opposition from several quarters.
However, Mr Naughten said the scheme should be delayed until its flaws are corrected.
"The minister may have got assurances from the senior Gardai, but it's clearly evident that the Gardai on the ground who are supposed to be implementing this legislation have not been briefed on it," he said.
"It is also the case that there are question marks over the constitutionality of it and, if it's the case that the Gardai are not being fully briefed, there will be mistakes made in actually issuing the penalty points."