Fine Gael's environment spokesman, Mr Ivan Yates, yesterday demanded to know why details of increases in motor tax were not included in Wednesday's Budget in the Dail.
"The Government was quite happy to announce the upside of their Budget, yet under the cloak of darkness late last night [Wednesday] Environment Minister Mr Noel Dempsey delivered the bad news to motorists," he said.
In a statement on Wednesday night the Minister announced the increases in motor tax of between 4 per cent and 6 per cent on private cars, and 6 per cent on goods vehicles, with effect from April. He said he was bringing forward legislation to "green" and rebalance the motor-tax regime.
Mr Yates said the public would not forgive the Government if it "took them for fools".
"The Government must now state what other budgetary measures, if any, are in the pipeline but were omitted by Minister McCreevy yesterday."
A spokesman for the Department of the Environment said the increase was not included in Mr McCreevy's Budget because it was not a budgetary matter. The revenue, he said, did not go to the Exchequer but to local authorities.
The statement from Mr Dempsey was released at 6.15 p.m. on Wednesday, he said.
The decision to increase rates of motor tax has been condemned by the Automobile Association as completely unnecessary.
Mr Conor Faughnan, of the AA, said it was "utterly unjustifiable" for the Department of the Environment to say it needed more money through road tax at this time.
Motorists already contributed about £3 billion annually to the Exchequer. Only 15 per cent of this was spent on transport generally.
"Road tax is a complete misnomer. The money collected disappears into the Exchequer as pure taxation," he said.
"This is an opportunistic tax levied on a captive audience. They have no choice but to use their cars and pay this tax."
The increases will be loaded on larger, less fuel-efficient cars, trucks and other vehicles. Owners of cars with bigger engines can expect their road tax to increase by 6 per cent.
Mr Faughnan said any suggestion that the taxes would have an environmental benefit were spurious because a modern two-litre car was 30 times less likely to cause pollution than a 10-year-old 1.4litre vehicle.
Mr Cyril McHugh, chief executive of the Society of the Irish Motor Industry, said if a significant proportion of the revenue was invested in local roads, the increased taxation would be less difficult to bear. "We would feel the motorist is fairly heavily taxed as things stand, and insufficient amounts of it go back into infrastructure."