In his victory speech last year, after winning a fourth election on March 17, there was a slight variation: he thanked his two sons for their help.

He was referring specifically to the elder of his two sons, Yair (his younger son from his marriage to Sara, Avner, is serving as a combat soldier in the IDF, while Noa, his daughter from his first marriage, keeps resolutely out of the public eye).

Until recently, Yair, 25, featured mainly in the gossip columns. A couple of years ago, the Israeli media was mildly scandalised by claims that the prime minister’s son had dated a non-Jewish Norwegian woman.

Recently, however, reporting on the young man has moved to the political sections of newspapers and TV news as he has taken up a place among his father’s inner circle of advisers.

Netanyahu junior has yet to give an interview but, according to sources within the prime minister’s entourage, he is politically to the right of his father and considered within the family “Sara’s son”.

Following his military service in the IDF Spokesman Unit, he was active in Likud’s youth section, but veteran members opposed giving him a leadership role and he returned behind the scenes, where he has much more influence.

Together with a small group of friends, some of whom served alongside him in the IDF, he has apparently taken over the prime minister’s new-media operations in Hebrew. Among the initiatives they have been involved in was the filming of the infamous “the Arabs are voting in droves” video on election day, which was posted on Mr Netanyahu’s Facebook page.

More recently, the Israeli media has reported that Yair influenced his father to take a more supportive position of Elor Azaria, the soldier accused of manslaughter after shooting a wounded stabber in Hebron, and to endorse a law which would prevent mosques using loudspeakers for the call to early morning prayers. He is also thought to be among those urging the prime minister to respond harshly to critical media reports.

The Netanyahu family’s spokesperson has responded that the reports on Yair amounted to the Israeli media expanding its “persecution” of Mr Netanyahu and his wife. He insisted that Yair is a private citizen whose affairs are no concern of the press.