The leader of Britain’s opposition Labour Party has turned down an invitation from Prime Minister Theresa May to attend a dinner this week marking the 100th anniversary of the Balfour Declaration. The Israeli Prime Minister Benjamin Netanyahu will be at the event, along with senior UK government representatives and members of various UK Jewish organizations.

Without giving a reason, Mr Corbyn declined the invitation and instead is sending his shadow foreign secretary Emily Thornberry.

As he has not given a reason for failing to engage, not only with an important event in history, but also with the leader of another country, it is left open to speculation as to his rationale.

There is not enough space here to document his five decades of opposition to Israel and support for those who oppose the country, including those who use terrorism, but any idea that the would-be Prime Minister of the UK is even-handed on the Israel/Palestine question is risible.

He has only ever been comfortable hosting groups such as Hamas and Hezbollah. Both organizations are regarded by numerous countries as terrorists, both have been called ‘friends’ by Mr Corbyn. He justified this term by saying it is important to engage with the different parties to the dispute. However, he does not extend this argument to the Prime Minister of Israel. In the event of the Palestinian President  Mahmoud Abbas coming to London it will be interesting to see if Mr Corbyn meets him.

In 2014 Mr Corbyn attended a wreath laying ceremony in Tunisia held to honour a Palestinian terrorist who helped organize the 1972 Munich massacre of Israeli athletes. He has shared platforms with rabid Islamist anti-Semites of the type who also call for homosexuals to be killed.

He has stood idly by whilst Jewish Labour Party members have been insulted, and anti-Semitism allowed to seep to the surface often disguised as ‘anti-Zionism’.  He responded to widespread allegations of anti-Semitism in the party by publishing the findings of an investigation described by most of Britain’s Jewish organizations as a ‘whitewash’. He then, in the words of the distinguished author Howard Jacobson, stuck his middle finger up to British Jewry by elevating the report’s author Shami Chakrabarti to the House of Lords as Baroness Chakrabarti. He then made her his shadow attorney general.

It is difficult not to draw the conclusion that the rationale to boycott the Balfour Dinner is because Mr Corbyn detests Israel. During his decades as a career politician he always has done, and always will.

Mrs Thornberry, who hopes to be Britain’s foreign secretary, could have used her late invitation to engage with the Israeli government and build a relationship for the future.  Instead she has made a statement suggesting she regrets that the State of Israel even exists saying “I don’t think we should celebrate the Balfour declaration but I think we have to mark it because it was a turning point in the history of that area and I think probably the most important way of marking it is to recognise Palestine.”

Her tone contrasts with that of the British Foreign Secretary Boris Johnson who, in celebrating the Balfour declaration, wrote  – “I see no contradiction in being a friend of Israel and a believer in that country’s destiny, while also being deeply moved by the suffering of those effectively dislodged by its birth. The vital caveat of the Balfour Declaration intended to safeguard other communities has not been fully realised.”

This was a grown up, even-handed position, recognising both sides’ point of view. The caveat referred to Lord Balfour’s words  –“ it being clearly understood that nothing shall be done which may prejudice the civil and religious rights of existing non-Jewish communities in Palestine…”

A case can be made that the only parts of the subsequently divided land where non-Jewish communities have equal rights in law (if not always in practice) is the part now renamed Israel. In Palestine, the embattled Christian Arab minority is shrinking, especially in Gaza. The Palestinian view is that no Jews whatsoever should be allowed to live in Palestinian territory.

That is germane to the debate overall, but not to the point made here which is that the British government is using this week’s dinner to work with the Israeli side of this divide whilst simultaneously reminding them of the need for a two-state solution and the suffering of ordinary Palestinians. The senior figures in the opposition indulged themselves with pointless gesture politics ensuring that if they come to power at least one side in the Palestine/Israel divide will have little reason to see them as an honest broker.