The famous TV series Game of Thrones has roots in French history: it was modelled on The Accursed Kings, a novel by Maurice Druon about the medieval French monarchy.

It is now French politics that looks increasingly like Game of Thrones. Or, at least, French far-right politics. Marine Le Pen, 46, the National Front's chairman since 2011, "declared war" on her father, Jean-Marie, 86, who founded the party in 1972 and ran it for almost 40 years. And Jean-Marie is striking back.

On the face of it, antisemitism is the issue. On April 2, Mr Le Pen reiterated on BFM TV a view he first made known in 1987, that "ascertaining whether there was such a thing as gas chambers was a small detail in Second World War history". Asked whether he retrospectively "regretted" having said such a thing, the elder Le Pen replied: "Absolutely not, because this is the historical truth."

Five days later, in an interview with the far-right weekly Rivarol, Mr Le Pen said that he would neither change his mind nor "crawl before the public" on these matters. Moreover, he praised Marshall Pétain's pro-Nazi regime - which was instrumental in the persecution and rounding up of Jews from 1940 to 1944 - and insisted that guilt over the Shoah was the main reason why France was not able to cope with its immigration problem. Finally, he resorted to classic Christian antisemitism to describe Marine Le Pen as a modern "Judas" and her advisers as a "Sanhedrin".

Ms Le Pen published a statement attacking her father's "scorched earth" and "suicidal" behaviour, and said that it went against the party line and the party's interests. As a result, she made it clear she intended to take action against her father, including barring him from running as the top National Front candidate in Provence in the December regional elections.

Several of Ms Le Pen's closest friends and advisers were even more explicit in their condemnation of Mr Le Pen.

Louis Aliot, the Front's vice chairman and Marine's partner, tweeted that Mr Le Pen's interview with "that nondescript antisemitic publication, Rivarol" was "absolutely scandalous". Florian Philipot, another vice-chairman and the architect of the National Front's current "left-wing" strategy, posted that the point of no return had been reached. The National Front's rank and file seem to agree: 86 per cent of NF supporters agree with Ms Le Pen and disapprove of her father's behaviour.

Many observers think that the real issue might be internal feuding within the Le Pen family.

While Marine managed to keep the National Front alive and even take it to new electoral highs (over 20 per cent of the national vote on average), she has a potential rival in the form of her younger, charismatic niece, Marion Maréchal Le Pen, 25, a granddaughter of Jean-Marie by another daughter. Marion seems to enjoy Mr Le Pen's support. She takes a much more right-wing stance than Marine on many topics.

A further working hypothesis is that there is no feud at all between Jean-Marie and Marine. The whole story may have been staged in order to boost Marine's image as a moderate - and to pave the way for Marion Maréchal Le Pen to become the party champion in Provence.