Why is diesel more expensive than petrol in the UK?

I realise there is probably some tax scam going on but how on earth do the government justify it?!?!
Answers:
NO it's the greedy oil companies that say they have trouble keeping up with demand!
because england is gay
they dont they just do it.
cos some of us put veg oil in our diesel instead and its only 60p per litre.the B***ards havent worked out how to catch us yet.
lol.
it used to be cheaper than unleaded, but the powers decided to make some cash a piss all the truck drivers off, don't you just love capitalism?
On balance, it's actually cheaper. It may be more pence per litre, but the fuel economy is better from a diesel engine so you will get more mileage from it. It should cost you less to run a diesel than petrol car.
about same in usa now.used to be a lot cheaper.
Because it's ingested and urinated out by small pygmys in south east asia before being shipped over on bamboo canoes by squirrels and then when it reaches felixstowe the pour it out onto the road and immigrants use straws to blow it up the A14 until it reaches a oil depot..well that's what I've heard.
This should answer some of your questions
http://www.dieselcar.com/pdf-files/artic.
Diesel is cheap , the tax Gordon Brown as put onit due to the fact more cars are run on it makes it dearer
I feel you.where i come from..deisel is much much cheaper!
It's always about supply and demand. Sometimes it's skewed by politics, but basically, somebody screwed up and made too much petrol. Now there isn't quite enough diesel to go around, so the price goes up.
because the oil companies dont rip us off enough by high prices if we all were diesel users they would not make as much profit and lets face it they really need the money poor sods
the oil companies make it so,if you drive a deisel car and get high M.P.G. they want you to fork out more for the gallon,it is known as legalised banditry
The government convinced us to use diesel because it's cleaner and cheaper than petrol. Once enough people had got their diesels', they decided it was not cleaner, and put up the duty on it. Who'd have guessed. Just keep your eye on the price of LPG when enough of us are using it.
It's good old Gordon Brown. He's moved on from Stealth tax to spite tax.
Most other countries realise that their economy depends on road transport, and nearly all HGVs are diesel powered. So , everywhere else they put less tax on diesel to help their economies. Private motorists using diesel are usually such a small percentage that their governments don't mind.
Not our Gordon though. He knows that our economy also depends on road transport, and therefore can be ransomed.
Gordon really is a very spiteful tax taker, and needs to be. Since there are now far fewer tax payers in the country than there used to, he has to take more from each of them. (Remember here that every new Public Sector job is another person removed from the potential list of tax payers. - Public sector workers are paid by taxes raised elsewhere and hence are not contributors. There are at least 500,000 more public sector workers now than there were in 1997)
As to justification, he doesn't justify because he doesn't have to.
The reason for high taxes is to pay for a the public sector, their gold plated pensions, and control freak Dictator Blair's obsession with regulations (over 100,000 new ones from him).
Diesel fuel consists of hydrocarbons of around 10 carbon atoms per molecule.

Petrol consists of hydrocarbons of around 8 carbon atoms per molecule.

Therefore a litre of diesel fuel, when burnt (in an engine or otherwise) will produce more carbon dioxide than a litre of petrol.
The government has applied a "carbon tax" on road fuels - so that the more carbon emitted, the more tax paid.

However, because diesel engines are more efficient, they produce less CO2 per km, even though they produce more per litre - hence the total tax paid per km is less.

CNG and LPG contain molecules with even fewer carbon atoms, so are taxed lower still.
after reading some of the answers i find the answers are in the question.
walk
It is a big tax scam, That is why we kick you guy to the curb 230 years ago, due to this tye of tax scams.