The coronavirus crisis means Birmingham is seeking to delay its crackdown on cars entering the city centre.
The city's Clean Air Zone (CAZ) was due in July, but the council has asked for government permission to postpone it until "at least" the end of the year.
The authority says efforts to tackle high-polluting vehicles have become a challenge as public priorities change.
Covid-19 is having a "profound impact" on the city, according to its environment boss.
Councillor Waseem Zaffar made his case to delay the CAZ rollout in a letter to Grant Shapps, secretary of state for transport.
Birmingham was among five cities the government called on to establish a clean air zone along with Leeds, Southampton, Nottingham and Derby.
Locally, the measure introduces a fee-paying area within the A4540 ring road, but not the road itself. Cars deemed high polluters are set to be charged £8, while buses and HGVs will attract a £50 levy.
In the correspondence, Mr Zaffar said he still believed the CAZ was the "most effective way of making a sustainable improvement to Birmingham's air quality".
But amid the coronavirus outbreak, he added: "Businesses are focused on trying to support their employees through an extraordinary situation rather than upgrade their vehicle fleets.
"Low income workers and residents are focused on ensuring they and their families stay safe rather than apply for exemption or financial incentive.
"COVID-19 is also creating a high level of uncertainty around our delivery partners.
"For these reasons we are requesting a postponement to the launch [of CAZ]."
Source: BBC