A highway-safety lobby is pressuring the U.K. government to avoid delays in next year’s introduction of real-world emissions tests of diesel cars.

The call by the national organization Brake comes after an industrywide investigation conducted for the Department for Transport found none of 37 cars tested met the European Union’s nitrogen-oxide (NOx) limit in real-world testing.

The department says levels of pollution were found to be much higher on the road than in the laboratory. Average emissions were five times higher than acceptable levels and some cars’ NOx levels were 12 times higher.

“The tests do show the widespread use of engine-management systems to prevent engine damage, which can lead to higher emissions in real-world temperature conditions cooler than those in the approved lab test,” Transport Secretary Patrick McLoughlin says in a statement.

The Vehicle Certification Agency tested a representative selection of the U.K.’s top-selling diesel vehicles.

“Existing lab tests designed to ensure emission limits are met have been shown to be inadequate and this is why the U.K. has secured a tough new Europe-wide ‘real driving emissions’ test,” the government statement says.

“From next year, vehicles will have to meet emissions limits in real driving conditions across a wide range of typical operating temperatures. This will improve consumer confidence in manufacturers.”

Brake spokesman Gary Rae says if automakers are serious about protecting the environment, then they must “cut the poison” being pumped out of their vehicles.

“I want the government to ensure that testing is rigorously enforced and tough action taken when vehicles do not make the grade,” Rae says in a statement. “Consumers are fast losing confidence with car manufacturers. Many drivers believe they have been cheated into buying diesel vehicles.”