In recent days, Benjamin Netanyahu has begun to speak about a policy issue he never mentioned before — pensions. In all his years in office, his focus has been mainly on security, diplomacy and geopolitics. He has paid attention to economics, too, but always the big picture: macroeconomics, Israel’s exports and balance of payments, and strong growth and employment figures.

One field that never seemed to interest him is social policy. In private, he is disdainful when such matters arise.

The school system is doing badly in the international tests? No problem, the IDF’s intelligence units will make sure there are enough highly-trained young people to keep the tech sector ticking over. A deficit in social security? Rising GDP will sort that out.

In the 2015 election campaign he responded to a State Comptroller’s report on the housing crisis by saying that he was dealing with “life itself”, by which he meant the Iranian threat.

Now, for the first time, he’s bringing up pensions in the election campaign — and there is a specific reason why. The biggest threat facing him now is not Iran, it is Avigdor Lieberman and his party Yisrael Beiteinu’s surge in the polls.

He is well informed of his former defence minister’s private promises to remove him from office. The refusal to join his government in April was just the first stage. Mr Lieberman is now planning to build a new centre-right coalition without the “natural partners,” the Charedi parties who have kept the prime minister in power.

To try and block Yisrael Beiteinu’s rise, Mr Netanyahu is going after its core Russian-speaking vote and their chief concern, as elderly immigrants, is their pensions. So the prime minister is promising that only his superior relationship with Russian President Vladimir Putin can ensure they get their full rights as new Israelis who spent their lives serving the Soviet Union. 

But there is something awkward about him speaking on pensions. It does not sit quite right. Perhaps it is the fact that the energetic leader, Israel’s youngest prime minister when elected, the only one to have been born after the state’s foundation, is now himself of pensionable age — 70 at his next birthday in October.

Mr Netanyahu, an addict of polling, is very aware of the thin line he is walking in trying to maintain his image, simultaneously of a seasoned, experienced statesman and a dynamic, youthful politician. That is why he spent years experimenting with hair colour and he never refers to the fact that he is a grandfather.

This weekend, he achieves a historic milestone: surpassing Israel’s founding leader David Ben-Gurion to become the country’s longest-serving prime minister, having been in office a total of 13 years and 128 days.

In public, Mr Netanyahu has belittled the date, saying it is meaningless. But in private he has taken to speaking of Ben-Gurion with a new-found passion, which is out of character for someone brought up in a Revisionist household where he was a bitter ideological foe. He is eager to be seen in history as the equal of the founder — but he knows there is a downside. 

Likud pollsters have been warning him since the 2015 election of “Bibi fatigue” plaguing right-wing voters, jeopardising turnout, the most crucial factor in any election. His solution has been to run fear campaigns of “the left” coming to power with the help of “droves” of Arab voters.

But Mr Lieberman, the ultra-nationalist, cannot be so easily tainted with leftism. So how does Mr Netanyahu maintain the balance, projecting the image of Israel’s experienced statesman while still looking youthful?

There is a delicious irony here. Look back 23 years to the first election Mr Netanyahu ran — and won — by a wafer-thin margin and it does not look as if he has aged since. His campaign managers portrayed him then as a man much older than his 46 years, with white hair and lighting to make his face look lined. He needed the gravitas of age. 

In a young country, Ben Gurion had no dilemma on how to campaign. In the election for the fourth Knesset in 1959, Mapai (an acronym of “The Worker’s Party of Eretz Yisrael”, the Labour Party’s previous name) ran with the slogan “Say Yes to the ‘Old Man”.

David Shaham, the late advertising executive who ran that campaign, explained in a 2008 interview that after a decade of independence “people had a feeling that things were beginning to work out, that the country’s security was more settled.” It worked so well that Mapai used it again in the 1961 election. 

Mr Netanyahu will not be running as the Old Man. Neither will he be publicly celebrating becoming Israel’s most veteran prime minister (though the sycophantic Yisrael Hayom freesheet owned by his patrons Sheldon and Miri Adelson is dedicating entire spreads to the milestone) because Bibi fatigue is simply too much of a liability.

As a student of history, he knows only too well that winning elections is not enough. Ben Gurion won five consecutive elections (Mr Netanyahu has won four and lost two, while the first election of 2019 was a stalemate) but was ultimately forced out by his party colleagues who were growing increasingly tired of the old man’s autocratic manner.

For now, Mr Netanyahu does not face a similar threat within Likud, but he always relied on the wider right-wing camp to cement his power-base. Now Mr Lieberman lurks there, determined to ensure that, although Mr Netanyahu is now the longest-serving prime minister in Israeli history, he never equals Ben Gurion’s five-victory record.