Mayor Sadiq Khan has been urged to introduce a diesel scrappage scheme to help small businesses upgrade their vehicles to new, cleaner models.

The call, from the Federation of Small Businesses, comes as the Mayor’s new £10 per day ‘T-Charge’ comes into effect.

Hailed by City Hall as “the world’s toughest emission standard,” the charge will be levied on top of the Congestion Charge and applies to vehicles entering central London which don’t meet Euro 4 emissions standards.

Mr Khan describes the scheme’s launch as “a major milestone” in his pledge to clean up London’s polluted air which is linked thousands of premature deaths each year.

Launching the T-Charge, he said: “I am transforming our bus fleet, getting rid of the oldest polluting taxis and creating healthier streets that will leave a lasting legacy for our children. But I can’t do this alone.

“I urgently need government to step up and face their responsibilities by delivering a diesel scrappage fund and a Cleaner Air Act that is fit for purpose.”

However Mr Khan is facing calls from the FSB to live up to his election pledges to be “the most pro-business Mayor” the capital has known and introduce his own scrappage scheme.

The organisation says its members are “disproportionately bearing the brunt of the cost of this scheme,” and adds that many worry it “will be the final straw that closes businesses and takes jobs” as they struggle to cope with “high property, employment and logistics costs.”

While stressing the FSB’s support for measures to improve air quality, London Policy Chair Sue Terpilowski OBE, said: “We call on Mayor Khan to recognise the pressures facing the capital’s small and micro business community and make it an urgent priority to put in place supportive measures including a small business diesel vehicle scrappage scheme.”