The UK Department for Transport (DfT) is to introduce a new 90-minute emission test for new models of diesel and petrol cars before approving them for use on the country's roads. 

With the introduction of the new test, the government expects to cut harmful nitrogen dioxide emissions by two-thirds for diesel cars. 

These new standards will be effective from 1 September. 

Under the old system, vehicles were tested in the lab on a rolling road in a process later founded to be tricked by a number of high-profile vehicle manufacturers. The new method will involve a real-world driving with emissions testing equipment attached to the exhaust pipe, with vehicles required to pass before being approved to go on sale in the country.

Vehicle fitted with the test equipment will be driven through towns, across the countryside and on motorways. 

"This will ensure all vehicles meet rigorous standards when driven on our roads, and we are going even further tightening requirements again in 2020."

UK Transport Minister Paul Maynard said: "We are taking strong action to clean up our air and these tough new emissions standards will reduce dangerous pollutants.

"This government has led the way in Europe pushing for on-road emissions tests, alongside a tough new laboratory test, to clean up the air in our towns and cities.

"This will ensure all vehicles meet rigorous standards when driven on our roads, and we are going even further tightening requirements again in 2020."

The government also noted that the nitrogen oxide emissions requirements for all new car models will be even stricter from 1 September 2020.

Last year’s diesel testing programme found that the existing Euro 6 diesel cars were emitting six times more nitrogen dioxide in the real world than in the lab.