The government admits air quality laws will be breached in 15 regions until 2020.
Londoners will have to wait until 2025 for pollution to enter legal limits.
Pollution levels in affected areas are a health risk to people on many of Britain’s busiest streets, especially those with heart or lung problems.
The government says the laws are unrealistically strict.
The BBC understands that it also believes the European Commission is partly to blame because it did not set proper limits on pollution from diesel exhausts in the first place.