The original sales target of 2,000 units in its first year in the UK has been slashed to 1,000, despite an extension of a £1,000 grant scheme for purchasers from TransportAction PowerShift.
A Toyota spokeswoman said: 'Although retail sales for the Prius have been strong, our fleet sales have tended to be one or two cars at a time. However, demand for our demonstrators has grown and we have doubled the size of our demonstrator fleet.
'Most of our corporate sales have been going to public sector fleets, and they can often take a long time to reach a decision. Also the uncertainty over the future of PowerShift grants might have had some effect. We hope extension of the grants to the end of the year will encourage fleets to choose the Prius.'
Despite the concerns, Toyota has also confirmed its first blue-light deal for the Prius - Hampshire Police will be running one of the vehicles as an unmarked car, buying the car outright with help from a £1,000 PowerShift grant.
TransportAction PowerShift agreed to support the Prius from its launch in October 2000 with cashback of £1,000 per unit for each customer- initially for the first 200 cars, but then extended to cover an extra 350 vehicles sold to the end of July.
Now Scottish fleets will be eligible for the grant through additional support which is being provided by the Scottish Executive.
Jonathan Murray, director of TransportAction PowerShift said: 'By extending our funding of the Prius until the end of the year, we hope more people will be encouraged to switch to clean fuels.'
- Powershift website