There is a special top step on the Green staircase called the moral high ground. Here stand Toyota and EDF .

Toyota has been snooty ever since releasing the Prius to an impressionable audience. EDF, or Electricite de France , is enormously self-righteous in telling anyone who cares to listen that there is not much point in having electric cars until such time as electricity is brewed from renewable feedstock.

The Frenchies are of course the largest users of nuclear power and able to claim that nuclear power into electric car batteries is about as green as it gets.

Yesterday the two teamed up and held court at Forbes House, headquarters of The Society of Motor Manufacturers and Traders , with the support of the UK government.

To be trialled in London: 20 [of 200 in Europe; 600 worldwide] Prius hybrid cars with the additional benefit of power-pack batteries that are rechargeable from the mains. The owner can either charge from a designated point on city streets or at home. They are called PHVs or Prius Plug-in Hybrid Vehicles.

The range is poor in comparison with that claimed by dedicated electric cars. It is only 12.5 miles. However, that comparison misses the point. The Prius will be able to be a pure electric for many mums on the school run who live within six miles of school. When she gets a call from her chum to go for coffee, she can divert from her 12 mile route by switching back to the electric/petrol hybrid mode that the regular Prius operates in.

Fussy way of doing things? Not really, said the Toyota techies. What they are intent on doing is building on what they have, and standardising as many components as possible in order to get PHVs to market as cheaply as possible.

Gerald Killmann, who runs powertrain for Toyota manufacturing in Europe, said he wants to be able to put a normal petrol or diesel Prius (or its successor) down the assembly line, strap on the hybrid kit if that is what has been ordered, and then the larger rechargeable battery pack in the case that the customer has ordered the plug-in version as well. Other manufacturers still have plans for electric cars that have special bodies or which need their own assembly facilities.

Toyota has enjoyed being out in front with Prius when it was the only affordable ‘electric’ car with urban chic. Now it wants a mass market and believes this is the route.

Killman said: “We have to develop a technology that does not depend on infrastructure.”

And, as good as his word, he is specifying standard connectors at both ends of his power cord that could be bought at B&Q. The car really can be plugged in anywhere to download that 12 miles of electric journey.

About 2,500 recharge points will be installed in London as soon as possible; 10 times than number within five years.

The London traffic commissioner has bought into the idea. So has the Department for Transport. Hence the three-way Toyota, EDF, Her-Majesty’s-Government collaboration which aims to support the plug-in programme.

Cars and charge points will all wirelessly beam information back to base. The triumvirate is keen to know what charging patterns are likely to emerge and whether consumers can be shifted by price to do all their charging at night off-peak.

The government’s support will be in the forms of infrastructure and subsidy. All parties were quite clear that, if the real cost of making cars was added to the sticker price, no-one would buy them. There has to be a CO2 reduction programme. Therefore there has to be subsidy.

  • The plug-in Prius has combined fuel economy of 108.6mpg and CO2 emissions of 59g/km. It uses lithium ion batteries, unlike the standard Prius’s nickel-metal hydride batteries, to offer an electric-only range of 12.5 miles at speeds of up to 62mph. A recharge takes two hours. Once the batteries are depleted while driving, the petrol motor starts to recharge them.