A review of the Government Car Service, which provides vehicles for ministers, is already underway and the first plug-in hybrid and electric cars will be deployed this autumn.

Shortly afterwards, another 135 plug-in cars and vans will be available for public sector fleets, including police forces, councils and the NHS.

All vehicles will be considered on a like-for-like basis, assessing whole-life cost benefits, and will be supported by a network of charging points.

The initiative will be led by the Energy Saving Trust’s (EST) green fleet consultancy team, who will analyse the travel patterns and job-use needs of the vehicles operated by Claire Spink, head of the Government Car Service.

Vehicles will be assessed by EST as they come to the end of their life-cycle and those which are suitable will be replaced by an electric vehicle, with the lease rentals being subsidised for the first two years of the agreement.   

Danny Alexander, chief secretary to the Treasury, said: 'I am delighted the Government Car Service is leading the move to electric vehicles and I will be one of the first in line to use one. This is the right thing to do, with much lower running costs and close to zero emissions, these vehicles will save the taxpayer money and be much greener. We are also investing significantly in ultra-low emission vehicles which will help ensure they play an important role in the UK economy as well as the environment.'

Baroness Kramer added: 'Government must lead by example. Today’s investment will see government switching a significant number of plug-in cars and vans into our fleets and leading the electric charge.'

In both phases, charge-points will also be installed to provide infrastructure support for the new vehicles. Cars and vans will be recommended on a like-for-like basis and the reviews will consider the whole life cost of the vehicles to ensure that each replacement makes economic sense.

The £5 million scheme for getting ULEVs into government fleets is in addition to the support for the Go Ultra Low campaign being delivered in partnership with vehicle manufacturers and the £500m announced by the Deputy Prime Minister in April 2014.