The drab and overcast banks of the river Thames in ­London on Monday provided the unlikely backdrop to the ­latest move by Hugo Chávez, Venezuela’s president, to extend his geopolitical ­ambitions.

Standing outside his offices in front of a red double-decker London bus, Ken Livingstone, London’s mayor, formally announced a scheme that would see PdVSA, Venezuela’s state-owned oil company, subsidise cheap transport fares for poor Londoners in a $32m (€23.75m, £16m) deal.