An Irish-born, left-leaning academic who is not Jewish is not most people's idea of a high-ranking Israel advocate. But, as chairman of the Anglo-Israel Association, Lord Bew is working at the forefront of building bilateral relations between the two nations.

Born Paul Bew in Belfast, the son of two doctors, he first visited Israel as a 17-year-old. His father had recently died and so he travelled around the world with his mother "to cheer her up". "It was more or less a year after the Six Day War," he recalls. "I was very impressed. It was the Israel of kibbutz - not the start-up nation. It was a democratic Israel; it was the Israel of the Labour Party. It was the first time people saw cabinet ministers who did not wear shirts and ties."

As a Cambridge University student, he read the works of Jewish academics and Marxists, including Ralph Miliband and Isaac Deutscher.

"You might describe me as a bog-standard left-wing intellectual," says Lord Bew, who was involved in the Irish civil rights movement. "None of us really thought about the Jewish world except for the Jewish intellectuals whose work we were familiar with and respected as young academics."

But the socialist position on Israel has dramatically shifted since Lord Bew was a student. It has turned from admiration of a new democracy in the Middle East to vehement criticism of a capitalist nation. The socialist movement is now littered with Israel boycott initiatives and empathy for the Palestinian plight, which often crosses over into anti-Israel diatribe.

Lord Bew - a former member of the Workers' Association and who took part in People's Democracy marches, says it was "quite common for young left-wing intellectuals to be pro-Israel because the Israeli political culture was so different. Israeli society and its economy have changed, that world has gone. Israel has to be what it is now to survive. It has to be a successful capitalist nation - the start-up nation, the hi-tech nation. But it is now less easy to defend in certain sectors of Western public opinion."

I meet Lord Bew, 65, at the House of Lords for afternoon tea. Calm in manner, he is already waiting at the entrance when I arrive. Over crustless sandwiches and scones, he says: "The argument against Israel tends to be purely negative and powered by antisemitism. I think the case against Israel has lost the socialist utopianism which Jewish left-wing intellectual signed up to. There is no longer a socialist utopian case against Israel."

A full-time professor of Irish politics at Queen's University Belfast, Lord Bew has taken note of the surge in anti-Israel activism on campuses across the UK. Of the boycott, divestment and sanctions movement against Israel, he says: "I pay a lot of attention to it. It is profound among the student unions. Once I was looking at my students who were running a boycott of Israel campaign, and thought: 'If your mum needed an operation and the hospital was using technology that had been developed in Tel Aviv, would you then be for this boycott?'

"While I accept that it is possible to be very critical of the policies of the state of Israel, you do have to ask yourself whether the coalitions that are built up in student politics to create this campaign are obviously antisemitic. If you look at the tone of the demonstrations, some of the chants, it is very hard to say that the broader movement does not contain antisemitic elements. I think people have to face up to that.

"I do not think the Boycott, Divestment and Sanctions Movement is going to work on universities. There are so many ties with Israeli scientists and academics that have real connections with each other that I think those ties are too strong to be broken by any campaign."

And Lord Bew, the former chairman of the British-Irish Association, recognises that some of the most vehement criticism of Israel comes from Ireland - where Israel's attitude to the Palestinians has been likened to the British colonial attitude to Ireland. "It is related to old-fashioned peasant antisemitism and it is related to the 'we support the indigenous people, not the imperialists'" stance, he says.

"Peasant Catholic antisemitism in Ireland is not too dissimilar to Poland - seeing Jews as outsiders with lots of money. On my own campus, there have been issues and of course it gets caught up in Irish politics - the unionists tend to be much more sympathetic to Israel and the nationalists not.

"The unionists were saying: 'if you attack Israel, you attack us because you know we support Israel'. It not an unreasonable argument," he laughs. Lord Bew was appointed a cross-bencher in the Lords in 2007 in recognition of his contributions to the Good Friday Agreement. If he could work through that, what would he do for the ongoing Israeli-Palestinian conflict?

"Nobody can believe anything other than: we are stuck with these two people living close to each other and we must be looking to have the best possible relations," he replies. "There is no possibility of a utopian resolution of this place. This is about managing the level of hate downwards.

"I strongly believe in a two-state solution despite all the difficulties. My background in Irish politics was the Good Friday Agreement so I believe in the historic compromise between people. I find it quite exasperating that if I am quite clearly committed to historic compromise in an area, why people are convinced I am not committed to historic compromise in another area."

Lord Bew took up the position at the AIA in 2011 at the invitation of one of his many Jewish friends. So close are his ties with the community that he eats in a kosher restaurant at least once a week.

But advocating Israel in his position is not an easy feat. "The hateful part of the defence of Israel is the assumption that you are opposed to Palestinian statehood or the human rights of Palestinians," he says.

"I have always tried for a measured tone. You know that being an advocate of Israel is going to be difficult; it is a difficult time. I think you have to take the view that you are in it for the long haul. I believe Israel is a progressive democracy that should be defended. You have to take a long-haul view of it, and I do take a long-haul view."