A Wellington man who has been fighting for a year to have his conviction and $30 speeding ticket reversed has lost his bid to argue his case in the Court of Appeal.

John Pomeroy was driving near a school on Naenae Road in Lower Hutt in February last year, when he was caught by a speed camera travelling at 55km/h in the 50km/h area.

He defended the charge before two Justices of the Peace and argued a tolerance of 8km/h should have been applied.

The JPs rejected the defence and imposed a $30 fine, plus court costs of $30.

Mr Pomeroy appealed their decision to the High Court, but lost. He then applied to the High Court for leave to appeal to the Court of Appeal, but his case was dismissed.

Finally, he sought special leave from the Court of Appeal to argue his case.

In a decision released today, Court of Appeal Justices John Priestley, Anthony Randerson and Alan MacKenzie declined the appeal.

In his submissions Mr Pomeroy had described his prosecution as "the apotheosis of police pettiness and pedantry".

However, the judges said as a matter of law, there was no tolerance to driving in excess of the speed limit.

"Mr Pomeroy's belief that there was a tolerance which gave him a defence to the charge was mistaken in law, and ignorance of the law is no defence."

The judges also dismissed Mr Pomeroy's argument he was rushing to find a toilet at the time of the incident.

"It might have provided a reason for his speeding, but not a defence," they said.