Nicholas Sarkozy has made a public apology after vandals defaced graves in a First World War cemetery in northern France with neon pink swastikas, SS insignia and other obscenities.

The French president called the graffiti covering 12 British and Canadian graves “revolting” and said in a letter to the Queen that it was an “odious act”.

He said he condemned “with the greatest firmness this horrible act” and asked that the Queen should pass on his sympathy and solidarity.

The cemetery holds the graves of more than 2,300 British soldiers killed in the trenches at the 1915 battle of Loos, including Queen Elizabeth’s uncle Fergus Bowes-Lyon, and author Rudyard Kipling’s only son John.

President Sarkozy added: "I hope the guilty parties are convicted with the severity appropriate to the seriousness of the deed they have committed."

A team has been sent by the Commonwealth War Graves Commission to remove the graffiti.

Although there have been other cases of desecration of Jewish graves in France, officials said they thought this was a one-off incident rather than a political act.

In 2009 the "Arbeit Macht Frei" at the entrance of the Auschwitz concentration camp was stolen and vandalised.