Northampton's taxis will be required to scrap their diesels and upgrade to electric and hybrid in as little as seven years.
A borough council strategy to cut pollution in the town has picked out Northampton's 850 taxis and private hire cabs as a main contributor to emissions - but want them to be "part of the solution".
But Steve Ward, a drivers' representative for the Northampton Private Hire Association, says Hackney Carriage drivers and cabbies who have just invested in a car will be "kicked into the dirt" by the plans.
The borough council's new Northampton Low Emission Strategy (NLES) reads: "Taxis operate mainly in the urban area where air pollution is greatest and often leave their engines idling on taxi ranks.
"We will seek to reduce access to the most polluting commercial vehicles whilst [promoting] an uptake of ultra-low emission vehicles."
It comes after a 2017 study found one-in-20 deaths in Northampton are attributable to air pollutants, specifically a poisonous diesel engine byproduct called nitrogen dioxide (N0x). Studies show pollution hotspots in Northampton could produce twice the EU legal limit for N0x annually.
The Government is at risk of being sanctioned for its N0x emissions if it does not get hem under control, which would impact local authorities who have not done their part to reduce pollutants.
In line with a national air quality plan set out last year, the council plans to set emission standards for taxis, meaning diesel cars older than 2014 will not be given licenses from December 2025 onwards.
Eventually, petrol cars and hybrids will also be phased out until only electric taxis remain in 2030. Charging points will also be built into taxi ranks across the town.
Meanwhile, the Government has announced a plan to ban all new petrol and diesel cars by 2040.
But Steve Ward said: "We feel the Government has been pushing drivers to buy diesel for years. Now the cabbies have invested in them, the Government's changed its mind.
"Electric vehicles are not the beauties they seem. Government policy turn around in a few months on diesel, who's to say it won't turn around again here?
"A new Hackney Carriage Hybrid costs £55,000. Meanwhile, when the cabbies try to sell their 'unclean' vehicles there will be no market for them."
The Northampton Private Hire Association is asking the council to give cabbies a more lenient deadline to upgrade their old vehicles.
The council will also consider creating a clean air zone in the town that would fine high-emission vehicles.
The NLES is still awaiting final apprival.