A Clean Air Zone that was due to be launched in Leeds during January has been "significantly postponed" due to a government delay.
Vehicle checking software required to make the zones operational and enforceable in both Leeds and Birmingham was expected to be delivered by the government by October.
The cities' councils say the tool has been delayed until December, which will put back the January start date.
Both authorities were asked to tackle air pollution as a priority after roads in the cities were identified as likely to fail legal air quality levels by 2020.
Leeds City Council said it had successfully met "a number of challenging deadlines" only for the government to "fail to meet its own commitments".
Car Smashes Into Bus Shelter Near Bradford McDonald’s
Bradford Man Charged with Heroin and Crack Cocaine Supply Offences
Drug arrests after police raids in Elland
Bradford City retain EFL Gold Award for Family Excellence
Major police operation targets theft and drug supply investigation
Culture at the Heart of Stockport’s Transformation
South Asian Art Exhibition Opens at Cartwright Hall
Men’s Mental Fitness Programme Launches in Blackburn
Council Calls for Tougher Fly-Tipping Sentences
Man Jailed for Raping and Exploiting Vulnerable Teen in Stockport
Free Midsummer Festival to Return to Milton Keynes
Bhangra Nights
Remix Saturdays
Legal Show
Alim OnAir