Who consumes the greater amount of fuel and has a greater negative environmental impact, the person who drives 3000 to 4000 miles per year in an SUV and spends their holidays and weekends in the garden, or the self-righteous driver of the small car who notches up 10,000 to 11,000 miles per year, has a long-haul trip to somewhere like the Maldives, the Galapagos Islands, Kenya, or the Australian outback once a year, a skiing holiday every New Year or Easter, and two or three weekend breaks a year in places like Prague, Dublin, or Vilnius, reached by low-cost budget airline? I think Malcolm Wicks is using a walnut to crack a sledgehammer. Peter Royce, Cambridge

I feel it is morally justifiable to introduce more taxes on large 4x4s and other polluting vehicles. It's absolutely absurd to argue that we have a right to do whatever we want in the time we are living in. The childish egotistic pleasures that Jeremy Clarkson reminisces of are fading as climate change becomes a real priority. In enforcing the "polluter pays principle", people will be forced to make a hard decision about their vehicle choice. I hope that taxation will be based on CO2 emissions - then it will not be solely 4x4s - it will include the Bentleys and the Jaguars as well. Blake Ludwig, London

Anyone like to suggest how I tow my horsebox with a Prius? Name and address withheld

I gather from the comments sent in already that 4x4s, particularly those bought for urban use, are nothing more than status symbols or style statements. So what? Isn't the whole point of living in a western, capitalist democracy in this age of freedom and comfort - the fact that we can afford to be frivolous? Should we be ashamed of ourselves if a bit of hard work gives us the means to afford a few trinkets, and squirrel our wealth away lest anyone should find out about it? And why not buy a car that says something about ourselves (even if the exact message it puts out is up for debate)? Our clothing, homes, food, drink and holiday destinations all say something about our status and style, so perhaps we should choose a one-size-fits-all approach for those things too. If these narrow-minded, envy-mongers are so offended by the sight of us exercising our hard-earned freedoms, I, for one, will not stand in the way of them emigrating to any of the totalitarian, communist States they apparently hanker after so fondly. Markus Lowe, Guildford

I think 4x4 drivers should pay much more for use in cities as they are not designed for city traffic. However, 4x4s are are central to many people's livelihoods and essential for those who live a rugged lifestyle. More tax is gained from those who choose, or have to drive them. A conversion to LPG would not allow those who travel to the Continent to use the Channel Tunnel. More damage is done to the environment by natural disasters like Krakatoa and Mount St Helens and the geysers of Iceland and New Zealand and let us not forget the emissions from aircraft. Frankly, it is the politically correct police out again. It would be preferable to get the juggernauts off the roads and on to an improved and efficient rail system, but it is much easier to target motorists. Name and address withheld

I've read many justifications from 4x4 apologists in this debate. The funniest is from those who say that the antis are just envious (which indicates to me that they did buy them as status symbols) and then list spurious practical reasons for owning one! But of all the stats and counter-arguments from the pro-4x4 correspondents, none have explained to me why they feel the need to drive in a vehicle that's lethal to pedestrians. Don't they care? Or is it a price worth others paying for their "right" to an unnecessary 4x4? Would they still not care if their child were pulverised in a 20mph impact by one? Paul Newbold, Sheffield

Once again we have a tax issue wrapped up in a theorised (and still debated and unproven) environmental issue. If the government really cared about the environmental impact of 4x4s or, indeed, any cars, then why have they just added a hefty increase to biofuel tax - a fuel that is carbon-neutral and therefore, according to the Government's own advice, not a source of environmental damage. It's all about money, nothing else. Jim Barnett, Farnborough

If 4x4 vehicles are as economical as their owners suggest, why do car manufacturers spend so much time and money reducing weight and refining aerodynamics in pursuit of improved fuel economy? I find it hard to believe that anyone could suggest that fuel economy in real life driving can come close to a car, or even a two-wheel drive MPV which does not have the weight and friction of a 4x4 transmission. The same engine fitted to a car and a 4x4 will always use less fuel in the car for an identical journey. Cars with high fuel consumption and air travel should be targeted also and not used as justification for the use of 4x4s. Name and address withheld

If we really consider the "issue" of vehicle emissions to be worthy of yet more punitive taxation (which, incidentally, I do not), why not make the tax based on the actual emissions produced rather than based on whether the vehicle happens to have a transmission that drives four wheels rather than two? But then I guess that wouldn't fit well with the true agenda here: good old fashioned socialist envy. Under such a system, it wouldn't be four wheel driven vehicles that were worst hit, but buses and the like of the smoky old 2CVs so beloved of these people. Name and address withheld

Martin Jones [see below] does us all a favour by giving real numbers about fuel usage by a Boeing 747. My own, slightly different, calculations show that on a trip to NY each passenger will achieve fuel consumption of about 90 mpg. My 4x4 - a Subaru Outback - does 30 mpg (when I am light-footed and on a long run), and often as little as 21 mpg in town. To match an international traveller I would have to drive three or four up always. This would be difficult, as I live alone, and I suspect that offering lifts to random persons at bus stops might be looked on askance. By the way, all-wheel drive is a safety feature in ice, snow or even the wet, in town or country. Also, the MoT has a test for emissions that my car must pass each year so no chance of inadvertent pollution there. In the absence of a satisfactory public transport system I will continue virtuously to mix and match my travelling behaviour. It seems this country's commentariat - politicos and journalists alike, even debate letter writers - can't live without a witch to hunt. Four by four owners seem to be the latest class to be sacrificed at someone's personal and somewhat totalitarian stake. Alan Ainsworth, London

What are we going to ban next? How about banning football, because moving that many people around the country just to watch twelve blokes kick a sheep's bladder into a cargo-net has to use more fuel than a whole countries worth of 4x4s, so if we ban that we can keep nice cars. Politics of envy and stupidity, nothing more, nothing less. Dave Murray, Walsall

Yet another thing for the halfwits in power to nitpick over. I thought we were entitled to freedom of choice, but instead we are bombarded by laws that suit those in power. New Labour will certainly never get my vote. Let's hope this bumbling minister isn't in power by the time anything comes of it. Martin Harrison, London

It is a personal choice. I do not agree with banning people from owning 4x4s. What next, ban sports cars? Just for the record, if you buy a car that consumes more fuel you do pay more in tax, at the pump and at the post office. People drive 4x4s because that is their personal choice. Why do others take offence? If it is because of perceived emissions, then cars are way down the list of polluters. If you want a valid point, harass the train companies as a train pumps out as much pollution as if every passenger drove a bus. Better still, buses are spewing fumes and yet no one complains. Get a life. Four by four drivers are only guilty of one thing - making themselves a target for busybodies. Name and address withheld