Diesel cars have not been tested for illegal emmissions during Northern Ireland MOT tests for 12 years, despite it being a legal requirement, it has been revealed.
An air pollution expert said that not to do them was “virtually criminal”.
The government is legally required to test emissions on diesels but the discovery, by BBC NI Spotlight, means there are potentially tens of thousands of diesel cars emitting illegal levels of pollution on Northern Ireland roads.
Both EU and Northern Ireland domestic law requires the government to test diesel cars using a specialist smoke meter.
The tests were introduced Northern Ireland in 2006 but suspended 12 weeks later due to concerns about health and safety in the testing halls.
The Driver & Vehicle Agency (DVA) said its staff do a ‘visual test’ where they make a ‘personal judgement’ about emissions.
Spotlight bought a second hand diesel car and booked a test, during which it was confirmed its emissions would be checked.
According to Professor Robert Lee of Birmingham University, failure to do the test means the NI government is breaking the law and may now face legal action in Belfast and Brussels.
Professor Harrison said: “This is a very straightforward test and it’s quite an effective way of picking up the grossly emitting vehicles. Not to do it, I would regard as virtually criminal,” he said.
The DVA’s chief executive, Paul Duffy, said: “Resuming the metered smoke test for diesel cars will require a significant investment programme, which will also provide additional capacity to address the growing demand for vehicle tests across Northern Ireland and which is currently underway.”
He said a new centre in Belfast equipped to do the test would open in late 2021 but upgrading the rest would require funding approval.
SDLP MLA John Dallat said the failure to do the tests was a “scandal” which required a “thorough inquiry”.
He added: “I’m sure there are very few people watching this programme that haven’t seen cars emitting huge volumes of black smoke and wondering how on earth those things are on the road.
“Now we know. If those tests were there, those cars would be gone.”