The SSP would also renationalise the railways and all public utilities in a programme of revived Socialist ownership.

BBC: Socialists pledge help for poor

Meanwhile, outside Opec, Russia's oil and gas bonanza has underwritten efforts by President Vladimir Putin to centralise and even renationalise the country's energy sector.

BBC: Oil refinery in Colombia

Indeed, the popular rising that inadvertently swept Mr Mesa to power last October was led by radicals who wanted to renationalise the oil and gas industries.

ECONOMIST: Bolivia's energy referendum