The grant comes into effect on 16 July, but car makers still don’t know which bands their cars sit in and what grants will be offered on them

The discounts will apply to eligible vehicles costing up to £37,000, with the most environmentally friendly vehicles seeing the biggest reductions, the Department for Transport (DfT) said. Carmakers can apply for funding from Wednesday, with the RAC saying discounted cars should start appearing at dealerships "within weeks".