Tehran scared traders by sounding a fresh note of defiance on 25 April, warning that it would begin concealing its nuclear programme if 'harsh measures' were taken against the country. The UN Security Council's deadline for Iran to suspend uranium enrichment activity or face possible sanctions expires on 28 April.

As US consumers become increasingly frustrated at high gasoline prices, President Bush in late April announced two measures to address the problem. He suspended deliveries of crude to the Strategic Petroleum Reserve (SPR) until the autumn and allowed individual states to waive temporarily new environmental fuel regulations, due to come into force in May. Neither cut much mustard with the market.

'We see the suspension of deliveries to the SPR as too minor to matter, and note the potential for distortions of investment to arise through the use of [fuel] specification waivers,' says Paul Horsnell of Barclays Capital. 'Given that the lack of refining investment

has become a major constraint, introducing measures that can lead to disincentives for investment can only be rational in the very short run.'

US gasoline supplies fell again by 0.9 per cent to 200.6 million barrels in the week to 21 April. Crude stocks also dropped marginally to 345 million barrels, but are 5.6 per cent higher than at the same point in 2005.

Producers and consumers met in Doha on 22-24 April at the International Energy Forum, during which they discussed spiralling prices. International Energy Agency head Claude Mandil called for investment in both crude and refining capacity.

OPEC president and Nigerian Oil Minister Edmund Daukoru made a statement reaffirming 'the organisation's firm and proven commitment to providing adequate supplies of crude to consuming nations, as well as OPEC's commitment to stabilising the market and realising its objective of maintaining crude oil prices at fair and equitable levels for the benefit of the world economy and the wellbeing of the market'.