A commitment to protecting the environment has become as necessary for politicians today as a commitment to kissing babies.The focus on green issues is a response to public concern about the possible effects of climate change in our planet.

But appearing to do the right thing is not always the same as doing the right thing.

Hybrid vehicles are increasingly the cars of choice for those who want to prove their green credentials. The Toyota Prius, whatever else it may be, is a status symbol for anyone who wants to prove they are among the planet-friendly.

However, its reputation may not be deserved. The car is produced overseas, and needs to be shipped half way across the world before graces our shores.

The inclusion of two engines inevitably increases the amount of material and energy expended in manufacture. And digging nickel out of the ground to produce the car's battery is a dirty and energy-intensive progress.

As a result, there is a disconnection between what the car's real impact on the environment and its reputation.

But these are questions which are rarely raised. It has the right image, and that's a major part of its appeal.

By contrast, Jaguars are often held up as the epitome of gas-guzzling vehicles.

In fact, as the manufacturer's recent award shows, Jaguar is leading the way in producing low-emission diesel vehicles.

This isn't to say that a Prius is a bad car or that people shouldn't drive it if they wish.

But it is right to challenge some of the myths about hybrid vehicles, and about pioneering firms employing thousands of British workers.

In particular, ministers should not be choosing cars based efforts to project the right image, especially when that image doesn't match the reality.

It's one thing to make a difficult choice in the name of the environment. It's quite a another to make a choice which will harm both the West Midlands economy and the environment, simply to follow the crowd.

MPs Sion Simon and colleagues point out that foreign governments tend to buy local products. This is a fair point, but Britain should continue to champion free and fair competition rather than giving in and adopting the protectionist approach of some of our neighbours.

However, on any fair assessment of the quality of their vehicles and their environmental credentials, Jaguar is more than capable of winning - if ministers look beyond the hype.