Business leaders have warned Mayor Ken Livingston that his plans would force many small retailers out of business, or at least out of London.
The Mayor was being "disingenuous" by pretending only 4x4 'Chelsea tractors', high-performance sports cars and people carriers would fall foul of the charge, the Federation of Small Businesses (FSB) said.
"The local electrician or the service engineer who needs a larger vehicle to carry his tools will be affected. The shopkeeper who needs to collect stock from the cash and carry will be affected. And for those based inside the zone, the annual charge could be as much as £6,000," FSB London transport spokeswoman Sue Terpilowski said.
A spokeswoman for the London Chamber of Commerce, added: "Independent retailers will not qualify for some of the discounts that the owners of fleets get. To put it bluntly: if you are an independent retailer based inside the zone and you need to visit the cash and carry, you will be hammered."
The London Chamber of Commerce is calling for the introduction of a 'window' in the middle of the day when the charge could be dropped.