This was discussed on the news this week.
Diesel prices are rising as crude oil has hit record highs above $134 a barrel, due to supply fears and an investor shift towards commodities
http://news.bbc.co.uk/1/hi/business/7411962.st m
A lot of what you pay at the pump is actually tax. Fuel duty around 60p and VAT on top of it all at 17.5%. So assuming a price of �1.13 per litre, less VAT is about 96p less fuel duty is 36p. This is the true price of fuel including production, transport and forecourt profit.