The oil market raised its head again yesterday as Iran decided to ratchet up threats to cut the supply of oil from the region.

It said it will stop oil exports to six European nations - France, the Netherlands, Spain, Italy, Portugal and Greece - after sanctions were imposed by the European Union against the Iranian energy and banking sectors.

Brent crude obviously spiked in the immediate aftermath of the news and remains just shy of a six-month high, but the real worry for all of us who use oil, or indeed fossil fuel of any kind, is if Iran will carry out its threat to stop the flow of oil from the Strait of Hormuz.

Iran's geographical situation means it stands guard on the narrow channel of water through which a fifth of the world's oil is transported.

Cut that off and we'll all be faced with a massive hike in oil prices.