While Nicolas Sarkozy makes the French presidency look increasingly like a one-man government, his former political rivals are having a more difficult summer.

Dominique de Villepin, ex-prime minister, returned from Tahiti to be placed under formal investigation for his role in the so-called Clearstream affair, an alleged plot to smear Mr Sarkozy and damage his chances of winning the presidency. Jacques Chirac, his former mentor, began his own holiday after being questioned by a judge investigating political corruption that took place while he was mayor of Paris.