Benjamin Netanyahu used an event with Orthodox primary school children at the weekend to promise an extension of “Jewish sovereignty” to the West Bank settlements — but it was not clear if he could fulfil it.

The visit to a school to mark the start of the academic year on September 1 is a customary ritual for Israeli politicians, but they usually do not speak politics.

But this year, only 16 days before the polls open, Mr Netanyahu departed from tradition, addressing the television cameras more than the six to eleven year-olds gathered around him in at the school in the settlement of Elkana, in western Samaria.

Upon greeting the children, the prime minister asked if any of them had lived in the Gush Katif settlements in the Gaza Strip. This was a miscalculation: Israel left the Gaza settlements in 2005, before any of them had been born.

But Mr Netanyahu ploughed on, saying that “this is the old original home of the people of Israel and we will build another Elkana. We won’t uproot anyone from here. There will be no more Gush Katifs, no more uprooting, and with God’s help, we will extend Jewish sovereignty over all settlements, as part of the land of Israel and part of the state of Israel.”

As election promises go, it was particularly vague.

There is no legal definition of “Jewish sovereignty” — unlike Israeli sovereignty — and extending that to the settlements contravenes the Oslo agreements that Israel has signed with the Palestinians. It would likely spell the end of any prospect for a two-state solution.

Mr Netanyahu made similarly vague promises on the eve of the previous election in April, but one of his senior ministers at the time: “Netanyahu has been in power for ten years now and has done nothing to annex the settlements and no planning to do so is going on.”

Sure enough, once the was election over, Mr Netanyahu refused to make any concrete commitments to annexation in his coalition negotiations with right-wing parties.

The prime minister has been making a blatant play for the votes of Yamina, the newly merged list of religious right-wing parties.

While Yamina has promised to support a Netanyahu-led coalition after the election, the prime minister does not trust some of its leaders, particularly Naftali Bennett and Ayelet Shaked, and is anxious to ensure Likud remains the largest party, so he can claim to have a national mandate to form a new government.

For that, he is happy to cannibalise his religious allies and has been holding campaign events in religious suburbs, speaking of how he studies Torah with his youngest son Avner every Shabbat.

His promise to extend “Jewish sovereignty”, without explaining what that means, is another example.

What it really means is that he will say anything he thinks can help attract votes.