Cubans are in no mood to party today as Raul Castro, the president, turns 78. They are suffering the toughest austerity measures since the post-Soviet crisis of the 1990s, despite diplomatic achievements that have left the US isolated in its tough policy towards the Communist nation.

Sweltering in Havana: darkened stores and offices are going without air conditioning into the early afternoon as the government tries to reduce power consumption

It has been just over a year since Mr Castro took over from his ailing brother Fidel with a pledge to improve people’s lives and remake one of the most statist economies in the world. But now the population is being called on to sacrifice by a government many view as old and bureaucratic.