Because I have four children, I have no choice but to drive a people carrier. When I bought it three years ago, I went for diesel as I thought it would be cheaper and better for the environment.

How wrong could I have been? It now costs just under £100 to fill up and the Government has announced that it wants to increase the tax on it, apparently for environmental reasons. Tucked away in the small print of the budget was the announcement that cars bought between 2001-2006, which emit over 186 g/km of CO2 will no longer be exempt from the highest rates of VED.

At a time when the motorist is feeling real pain at the pump, this significantly increases the tax bill for people who bought cars up to seven years ago.

I am not alone: indeed 1.1 million cars will see VED increases of £220 or £245 between 2008 and 2010. And what is the so-called environmental gain for this pain? Treasury projections show that, thanks to these measures, carbon dioxide emissions in 2020 will be reduced by less than one per cent of total vehicle emissions.

Rather than engage people with the very real need to reduce emissions, this clumsy and underhand approach is likely to alienate them. It just seems to be about the Government wanting to raise more tax. Rather than punish people for choices they have already made, the Government should be giving us more positive incentives to "Go Green" when we next make a big decision such as a new car.

And while it is rethinking this proposal, it should also look carefully at sensible Conservative proposals to change the level of tax on fuel in response to movements in the oil price. Because we need some stability in prices and because motorists deserve a break.