When the UK voted in support of UN resolution 2334 just before Christmas, it seemed unlikely — to put it mildly — that Theresa May’s government might come to be recognised as the most solidly pro-Israel in British history.

As a senior communal leader said at the time: “If Labour wasn’t so toxic, the Tories might have blown 20 years of work in one vote.” And yet when a Whitehall source told me this week that “If you thought Stephen Harper was pro-Israel, just you wait”, it was entirely credible.

Mr Harper, who was Canadian PM from 2006 to 2015, was perhaps the most serious vocally supportive foreign ally Israel has ever had.

There may soon be a rival for that accolade.

Since voting for the UN resolution, UK policy has taken a very different turn. Number 10 and the Foreign Secretary are now open — almost — in making clear the vote was a big mistake. At the very least, their actions since show a willingness to fight Israel’s battles in international forums with an unprecedented relish.

Immediately after the vote, the then US Secretary of State, John Kerry, launched a withering attack on the Israeli government. To the astonishment of seasoned diplomacy-watchers, he was then unambiguously attacked by the British government.

Two weeks later, the government’s response to the Paris “peace conference” was intended as a direct contradiction of its vote for Resolution 2334. Middle East minister Tobias Ellwood was told not to attend; the British delegation comprised just two diplomats from our embassy in Paris.

Not only did the UK refuse to sign the concluding communiqué, it also issued a damning statement, highlighting the government’s “particular reservations about an international conference intended to advance peace between the parties that does not involve them — indeed which is taking place against the wishes of the Israelis”.

Now this latest move, making clear that the UK will call out and vote against the UNHRC’s ludicrous anti-Israel partisanship.

My Whitehall source confirms that there are two main drivers of this new-found clarity in British policy.

First, Mrs May herself. Oddly for a PM, her views on many issues are still somewhat unknown. Until recently, there was nothing to suggest she was any more instinctively supportive of Israel than most other Conservative MPs. Her actions show that she is.

But another key to this more pugnacious British support is the attitude of Nick Timothy, Mrs May’s joint chief of staff. As my source put it: “If he was a journalist, and he was Jewish, you could imagine him editing the JC.”