Hugo Chávez, Venezuela’s president, broke new ground in his campaign of global oil diplomacy on Monday when London mayor Ken Livingstone announced half-price bus travel for poor Londoners, funded with millions of Venezuelan oil dollars.

An initial one-year deal will see Petróleos de Venezuela Europa, the European arm of state oil company PdVSA, spend up to $32m (€23.75m, £16m) to subsidise bus fares for residents in the UK capital who receive low-income welfare payments.