Saudi Arabia’s powerful oil minister, Ali Naimi, made a rare intervention into overheating oil markets on Tuesday, declaring that high oil prices were “unjustified” and vowing that the kingdom would boost its output by as much as 25 per cent if necessary.

As the west’s nuclear stand-off with Iran escalates, oil prices have rallied this month to a post-2008 peak of $128 a barrel with markets bracing for European Union sanctions on Iranian crude that could knock out a chunk of global supply.

Speaking to reporters in the Qatari capital Doha, Mr Naimi said he wanted to “dispel this pessimism in the market” and the widespread fear that the world could see a repeat of 2008’s oil price increase which was a harbinger of the global recession.