Next Thursday, Israel's Likud party will hold primaries for its presidency and, for the first time in 14 years, someone is trying to dethrone the country's long-serving premier Benjamin Netanyahu as party leader. The most striking thing about the challenger, 52-year-old Gideon Saar, a former interior and education minister, is how little he is known abroad, probably due to his poor English skills compared to Mr Netanyahu. Yet the Washington Post crowned him a "wildly popular minister".

In fact, he has twice won first place in Likud primaries. Mr Saar is also popular outside the party: Surveys show 33 per cent of the general public favour him as Mr Netanyahu's replacement. The opposition media has hailed his candidacy, even though he could serve as a perfect target for the opprobrium of liberal Israelis.

Mr Saar has taken more conservative stances than the incumbent prime minister. As a teenager, he joined the ultra-nationalist "Tehiya" movement to protest against the evacuation of Israeli settlements in Sinai as part of the 1982 peace treaty with Egypt. He rejects the two-state solution as an "unhelpful illusion", supporting the annexation of the West Bank. The most he is willing to concede to Palestinians is limited autonomy in a federation with Jordan.

The former journalist and lawyer also ordered shops to be closed in Tel Aviv on the holy weekday Sabbath when he was minister of the interior - an expression of his ostentatious return to orthodoxy. This principled stance goes far in explaining his appeal to traditional right-wing voters.

But pragmatists and secularists have also been won over by the youthful-looking conservative. In contrast to Mr Netanyahu, this son of Argentinian immigrants has forged warm personal ties across the political spectrum. He posts selfies from rock concerts and doubles as a DJ in bars.

Mr Saar's biggest plus, however, seems to be his demeanour, which even political opponents unanimously describe as "extraordinarily decent". While Mr Netanyahu stands accused of corruption, routinely attacks the media, police, and judiciary and incites his supporters against every opponent, Mr Saar sticks to moderate language and unflinching support for the rule of law.

"We had many disputes," former education minister Juli Tamir of the opposition Labour party told the newspaper Haaretz. "But he always went by the book" - unlike Mr Netanyahu, "who has broken the rules completely".

While the Prime Minister does not tolerate opposition, Mr Saar is "very right-wing, but does not need everyone to agree with him", said Mrs Tamir.

Mr Saar is now striving to convert this appeal into political power. Following two parliamentary elections this year, after which Mr Netanyahu failed to form a coalition government twice in a row because the opposition categorically rejects him, Mr Saar has told Likud members that "whoever votes for Netanyahu is casting his ballot for the next opposition leader". The challenger's most important claim is that only he can build the alliances that will keep Likud in power.

So far, only four of Likud's 32 MPs have sided with him, alongside the powerful chairman of the party's central committee. Most pundits, therefore, give Mr Saar only a slight chance of beating Mr Netanyahu who, however, appears to be concerned about the outcome of the primaries.

If Israel's most astute tactician is concerned, the race seems to be worth watching.