Thousands of motoring cases could be dismissed after a High Court judge found a section of the Road Traffic Act concerning fixed charge penalty notices was unconstitutional.
As many as 28,000 cases could be affected by the finding, which was made after legal challenges were taken by two motorists who received convictions for driving while using their mobile phones.
In both cases District Court judges convicted the motorists even though they never received an initial fixed charge penalty notice.
This was because section 44.10 of the Road Traffic Act 2010, as amended, says a person served with the summons cannot use the defence of showing that he or she was not served with a fixed charge notice first.
If the motorists had received this notice, they would have been able to pay a €60 fine, accept three penalty points and avoid a court appearance.
But by virtue of being summonsed to court for not paying a fixed charge notice they never received, both ended up with a higher fine, five penalty points and a conviction.
In a written judgement, Ms Justice Úna Ní Raifeartaigh found the section of the Act was not compatible with Article 38.1 of the Constitution, which states no person shall be tried for a criminal charge save in due course of law.
The judge said the section had the effect of creating "an internal contradiction" such that if a motorist proves they were not served with the notice, one provision tells a district judge to dismiss the charge, while another tells the judge to convict.
A large number of cases are understood to have been on hold pending the outcome of the challenge. It is thought many of these could now be dismissed.
Ms Justice Ní Raifeartaigh initially indicated her intention to make the decision three weeks ago. But because she was aware it would have a widespread impact, she deferred finalising her judgment so the State would have time to lodge an appeal or amend the legislation.
However, when the judgment was delivered yesterday, it was still unclear what the State's response would be.
David Staunton BL, for the DPP and the State, said about 28,000 prosecutions could be affected and a view had yet to be taken on what the "appropriate remedy" would be.
Having heard from Mr Staunton, and from Feichín McDonagh SC, with Brendan Hennessy BL, for the applicants, the judge said she would allow the sides until November 19 to consider the judgment and would make final orders on that date.
In a statement, the Department of Transport said it was examining the judgment.
It did not respond to queries regarding whether it was considering an appeal or an amendment to the legislation.
While the decision could impact thousands of cases currently before the courts, it will not open the floodgates to the large-scale quashing of convictions and cancellation of points. To stand a chance of successfully appealing a conviction in the Circuit Court, a motorist would have to show they raised in the District Court the fact they did not receive the initial fixed charge penalty notice.
Another avenue would be to bring High Court judicial review proceedings, but these are usually limited to decisions which occurred in the past three months.
In her judgment, Ms Justice Ní Raifeartaigh suggested one possible solution would be to amend the legislation to confer a degree of discretion upon a District Court judge in sentencing so they could address "the various practical situations which may arise".
She previously said one middle course would be if the District Court judge retained a discretion to impose a fine and penalty points at the level of the first fixed charge penalty notice.