Greater Manchester's Labour leaders have released new proposals for the planned Clean Air Zone - including scrapping charges.
In a letter to Boris Johnson, after accusing him of playing "dishonest politics", Mayor of Greater Manchester Andy Burnham, set out the party's position ahead of talks with the government.
Alongside making the Clean Air Zone (CAZ) a "non-charging zone for any vehicles", they also say they want to remove all vans from the plans.
He added that, with government support, the city-region "could achieve" the air pollution levels needed by the deadline.
"In our proposal to Government, Labour will exempt all vans (LGVs) from any clean air zone," the letter said.
"Given the additional time we have secured from Government, this now means that the inclusion of vans should not be necessary.
"We will not support their inclusion and, if the Government wishes to include them, they will have to impose it.
"This exemption will be in addition to private cars, motorhomes, horseboxes, motorbikes and mopeds.
The letter continued: "Labour will press for a non-charging zone for any vehicles.
"Should the Government impose charges, we will only accept them for a Category B clean air zone if the Government provides full financial support to enable individuals and businesses to upgrade their vehicles and with sufficient time being provided in light of the supply chain issues.
"Ultimately it is for the Government to decide - as they did with the previous scheme. But we have made our position clear."
The controversial plans to charge motorists to enter the 490 mile area - which would have been the largest in the country - was set to be launched in May.
But it was delayed in February after concerns meeting pollution targets too soon could put many local firms out of business.
Taxi drivers and small business owners said the additional charges created by the Clean Air Zone (CAZ) would destroy their businesses, and complained they were not being offered enough assistance to buy new lower-emission vehicles.
Charges would have included £60 for HGVs, buses and coaches, £10 for vans and £7.50 for taxis and private hire cars.
Following the concerns and talks between Burnham and the government, it was agreed to move the deadline set for Greater Manchester to lower air pollution below legal limits by two years to 2026.
Greater Manchester leaders are now working with the government to design a 'substantially different' scheme.