According to the Vienna Convention of 18 April 1961 and the decree of 1 June 1979, the primary role of the head of a diplomatic mission consists of "representing the sending state for which they are accredited". However this has more than one possible meaning.
"The ambassador... represents the President of the Republic, the government and all the Ministers" Decree of 1st June 1979.
The Ambassador represents the whole of France
Originally, the ambassador represented his sovereign to another sovereign. It is why homage was always paid to him, being addressed not to him personally but to his country. Today, in the host country, the head of mission always acts as the representative of his head of state. However, in a democratic regime, it means that he represents not only his government, but also the whole of France, in its universality and in its diversity. For this reason, the tradition in France is that the ambassador is required to have no political allegiance. To represent his country also means that he must always be ready to accept anything that happens, particularly those things that could be open to criticism in the host country. This responsibility may include the risk of facing demonstrations, harassment, the threat of being taken hostage and even being a target. Finally, being a representative is offering the best possible image of one’s country in public and in private, as the head of mission continuously acts as a representative. It does not mean that the three-piece suit is always required dress, on the contrary, in many countries, the ambassador is more often in short sleeves than in evening dress. And if he plays rugby, he will be a fitting representative when he plays rugby - ...as long as he plays well!
"Previously it was necessary to listen to states, governments and all that was official. Today, it is also necessary to listen to the people..." Speech by the President of the Republic at the annual meeting of Ambassadors on 26 August 1998.
The Ambassador is a representative to the whole of the host country
The head of mission represents his country to the receiving state, that is to the government, or in the case of an international organisation, to the management bodies and to other heads of mission. In the second case, the task of representation is less onerous. However, in an embassy, representation is in general to the whole country, as in a democratic regime everyone is supposed to contribute to a greater or lesser extent to drawing up foreign policy. The ambassador therefore has an interest in meeting as many people as possible, in being seen in all sorts of places and in all sorts of environments. It is easy in that he receives many invitations. However, he has to choose between those that will provide useful contacts and those which, on the contrary, are counting on him to bring some credibility to an event that is lacking it. In a democracy, the ambassador usually maintains regular contact with the opposition. In places where the opposition is clandestine, the ambassador is faced with a dilemma. He cannot ignore the opposition, which are likely to become the government of tomorrow and who may already have his sympathy. Neither should he be accused by the authorities of the host country of encouraging subversion, in contravention of his diplomatic status. Solutions have to be found on a case by case basis. The golden rule is that a diplomat acts in the open.