At Sussex in the 1960s, the historian Asa Briggs – who is still going strong in his 93rd year – recruited a motley crew of maverick dons. Their brains and personalities secured his new university’s reputation as an interesting place to be.

The art historian Quentin Bell, for example, sealed a lasting connection between Bloomsbury and the university. The publisher Peter Calvocoressi, like Briggs a veteran of Bletchley Park, was recruited to teach international relations. Neither would have mentioned Hut 3 outside Briggs’s office and yet another unorthodox recruit had connections with the security services that few colleagues could have suspected. Norman Mackenzie, the former New Statesman staffer who died on 18 June, no doubt boasted a file in MI5’s archives – but as suspect or agent?

Briggs considered Norman’s 20 years as Kingsley Martin’s assistant editor a suitable apprenticeship for teaching politics. Norman retained close links with the NS and became an authority on the paper’s founders, Beatrice and Sidney Webb. In the great Fabian tradition of marital and intellectual partnerships – the Webbs, the Hammonds, the Coles – he and his first wife, Jeanne, wrote a fascinating group portrait of the worthiest progressives in late-Victorian London. They followed up their biography of H G Wells with a history of the early Fabian Society, after which they began editing three volumes of the Webbs’ letters and four of Beatrice’s diaries.

The Mackenzies took pride in their monumental act of scholarship and praised Norman’s secretary as the one person able to decipher Beatrice Webb’s scrawl. Regrettably, I can’t recall this woman’s name but I can remember that her regular job was supporting the now Professor Mackenzie in his role as director of the School of Education.

Norman oversaw teacher training at Sussex for a decade and his appointment was a shrewd move by Briggs. Sussex operated a model ahead of its time, with postgraduate teacher trainees spending four days a week in school and one back on campus. The director adopted a hands-off approach to all matters vocational, leaving his suitably qualified staff to get on with supervising their students and conducting classroombased research.

Norman’s role, given his long-standing interest in education policy, was to advise the Labour government and, in particular, the then education minister, Shirley Williams. After the Conservatives’ victory in the 1979 general election, his Whitehall days were over and he spent more time in his office. That office was where I had spent much of the previous year working on my doctoral thesis. Norman was extraordinarily generous and supportive as I researched the history of the fledgling NS, mischievously planting ideas (“Go to Kew and see if Clifford Sharp was a spy” – like he was, perhaps?) and allowing me open access to the Webbs’ transcribed correspondence.

He was great company and my one regret is that I was so preoccupied with the paper’s early editors that I didn’t ask more about his own experiences. For example, now that I know that he trained at Osterley Park with George Orwell in late 1940, I wonder how seriously he took Tom Wintringham’s vision of the Home Guard as a revolutionary people’s militia.

At the start of 1980, Norman offered himself as the external examiner for my PhD and it was a sign of the times that nobody suggested a conflict of interest. The night before the viva,my interrogator telephoned to say that the thesis was fine so I should relax and enjoy the day, at the end of which he would provide the celebratory champagne – again, a scenario inconceivable today but a measure of the man.

In the magazine's leader the week after Norman Mackenzie's death, editor Jason Cowley wrote:

Norman Mackenzie, who has died aged 91, joined the New Statesman as assistant editor in 1943, having been recommended to the then editor, Kingsley Martin, by Harold Laski at the LSE. Norman worked on the paper for nearly 20 years before becoming an academic at Sussex University. He helped found the Open University, edited the diaries of Beatrice Webb and was the author of biographies of Charles Dickens and H G Wells. His political journey from the Independent Labour Party and the Communist Party to Labour and then the Social Democratic Party was complex and fascinating.

I got to know him only at the end of his life, when he was in poor health and knew he had a few months to live. I found him lucid, witty, acerbic and generous in his advice and guidance. He told me he stopped reading the NS when it embraced what he called the “silly left”. He had recently become a subscriber again: “It’s like coming back to the place after 30 years away to find someone has been polishing the doorknobs.”

Norman lived to read the centenary issue and kindly sent the editorial team a congratulatory card: “Was there ever such a progressive magazine!”

He was a last, cherished link with the old world of Orwell’s London and Kingsley Martin’s NS. His friend the historian Hugh Purcell said: “He died in the morning, having said to Gill [his wife], ‘Death is a swindle if a man cannot have a whisky in his hand.’”