Exactly 35 years ago, the Arab oil embargo sent western economies into their worst downturn of the postwar period. So some unease is understandable as natural gas behemoths Russia, Iran and Qatar seek to start a club with eerie similarities to the Organisation of the Petroleum Exporting Countries just as another nasty slump takes hold.

On paper at least, the budding "Gopec" appears nearly as formidable as the 48-year-old oil cartel. The troika control 55 per cent of known natural gas reserves - about the same proportion of crude reserves held by the three leading Opec members. North America and non-Russian Europe have only 9.6 per cent and are increasingly reliant on gas for heating and power generation.