Harold Wilson would be "ashamed" of Labour's present anti-Israel attitude and the presence of antisemitism within the party's ranks, his former colleagues have claimed.
Speaking ahead of a series of commemoration events planned to mark what would have been his 100th birthday next Friday, Labour peers said Lord Wilson would have rejected many of his party's current policies and the endorsement by some of a boycott.
Lord Bernard Donoughue, who was a senior adviser to the late Prime Minister, said: "He would have been shocked and appalled by what's happening on the hard left of the Labour Party because he was a strong supporter of the Jewish community and a great supporter of Israel.
"For the Labour Party, or left-wing elements of it, to now be flirting with antisemitism is an appalling development."
Lord Donoughue said Lord Wilson would have rejected boycott policies and, as a former Oxford University student, "he would have been appalled by the antisemitism allegations in the Labour club and would have called upon the university authorities to take a firm stand".
Lord Donoughue recalled a conversation between himself, Lord Wilson and his press secretary Joe Haines in Downing Street in 1974.
"It was shortly after the Yom Kippur War. Joe and I told Harold that we would happily volunteer to fight for Israel if she were under threat of extinction. Neither of us are Jewish but that was the strength of our feeling.
"He was very sympathetic to that point of view. He was a great supporter of Israel."
The peer's comments were echoed by former Labour chairman Lord Tony Clarke.
An ex-trade union official, Lord Clarke said: "I think [Lord Wilson] would be ashamed that we seem to have lost our way on Israel.
"His support of Israel was never in doubt. He realised the responsibility that the Labour Party had in the run up to the creation of the state 68 years ago.
"Israel is built on the founding principles of socialism in this country."
Lord Clarke recalled discussing Israel with Lord Wilson while campaigning as a parliamentary candidate in 1974.
"He was very interested in my first visit to Israel just before the Yom Kippur War," Lord Clarke said. "He was pleased I came back full of energy to help form a Labour Friends of Israel branch in Camden. He said: 'Good luck to you my boy.'"
Lord Wilson, a former president of Labour Friends of Israel, was said to be unwavering in his support for the Jewish state.
While his eldest son Professor Robin Wilson told the JC he did not recall discussing Israel with his father, it was the former Prime Minister's youngest son, Giles, who inherited his father's passion for Israel.
Aged 24, Giles, a qualified teacher turned train driver, went to work on Kibbutz Yagur in northern Israel during the Yom Kippur War. There he learned Hebrew, which he is now said to speak fluently.
Lord Wilson developed strong friendships with leading Zionists including Shimon Peres, who once described him as "a true friend of Israel".
He was also close to Lady Valerie Cocks, who was the founder of Trade Union Friends of Israel, co-founder of the pro-Israel peers group and an active LFI organiser and fundraiser during Lord Wilson's leadership of the party.
Lady Cocks remained friends with Lord Wilson until his death in 1995.
Over Friday-night dinners at the home she shared with her late husband and former Labour whip Lord Michael Cocks, they discussed Israeli politics and bilateral relations. She recalled: "How many friends of that calibre did we ever have?
"He loved Israel and went on being president of LFI until he couldn't any more. He backed us in any way he could. I never had to ask him to say anything pro-Israel - it came naturally.
"He spoke about Israel in the most loving, warmest possible way."
Lady Cocks still visits his widow, Mary, every weekend at her home in London, which she described as "a shrine to Harold".
Lady Cocks said: "Mary still talks about him being in LFI. I always tell Mary: 'Not only do I like spending time with you, but look at what we owe you and Harold.'"
Lady Cocks said Labour was now a changed party. "There was a different feeling in Labour back then - there was a pro-Israel feeling.
"Harold Wilson would not have kept so amazingly silent as everyone is keeping. Why do more Christians not realise that the only place where fellow Christians are safe in the Middle East is Israel?
"Why doesn't Jeremy Corbyn say one word of pity for his fellow Christians? How is it possible that every British politician isn't screaming about it?"