The FTA is calling for tax cuts for small operators and a national scrappage scheme to help firms meet the cost of operating in clean air zones (CAZs).

The call comes ahead of the government’s air quality plan announcement next week, which is expected to lay out plans to set up CAZs in cities across the UK.

The FTA fears restrictions on older diesel vehicles in the CAZs will hit smaller operators hard, many of whom operate vehicles that do not meet the Euro-6 standard demanded by the zones.

It estimates the additional cost of compliance could be more than 150% of annual turnover for some of its smaller members.

FTA national policy head Christopher Snelling said: “The proposed CAZs pose a serious risk to the viability of many small businesses based in these zones, and a risk to jobs and local prosperity.

“When the CAZs are introduced, there will only be five years' worth of compliant HGVs in the national fleet, meaning specialist operators and small businesses, which tend to purchase second hand, will face a cost burden if they are to upgrade vehicles automatically.

“The situation will be worse for vans, where only two and a half years’ worth of compliant vehicles will be available. This is not long enough to create a second-hand market in compliant vehicles, and thus requires an immediate purchase of a new vehicle, threatening the way of life for many small businesses.”

Snelling said FTA members believe the government should take some responsibility for the financial impact the new legislation and zones will create.

“Air quality is a national problem and there should be national measures to solve it. Tax breaks or a scrappage scheme funded by the government could help business and diesel car drivers cope with the changes and reduce the need for local restrictions,” he said.

London's mayor Sadiq Khan has previously called for a scrappage scheme.