Prominent history professor Niall Ferguson was facing fresh claims of homophobia on Sunday night after it emerged that he has a history of deploying gay smears against economist John Maynard Keynes.
Professor Ferguson, 49, a British-born Harvard academic, shocked an audience at a conference when he implied that Keynes did not care about the future of society because he was gay and had no children.
Over the weekend the conservative thinker apologised "unreservedly" for what he described as "stupid and insensitive" statements during the Altegris Strategic Investment conference in California last week.
But other academics questioned Professor Ferguson's claim that the remarks were an "off-the-cuff" mistake, pointing to derogatory comments the historian had made about Keynes's sexuality in a book published in 1998.
In his critically acclaimed book The Pity of War Professor Ferguson wrote: "Though his work in the Treasury gratified his sense of self-importance, the war itself made Keynes deeply unhappy. Even his sex life went into a decline, perhaps because the boys he liked to pick up in London all joined up."
Yesterday Ben Summerskill, chief executive of the leading gay rights charity Stonewall, and human rights campaigner Peter Tatchell both condemned the historian's views and questioned his position at Harvard.
"I'm glad Ferguson has apologised for his homophobic slur against Keynes. However, it is shocking that such casual homophobia apparently exists in high academia. His remarks are what we might expect from a pub bigot, not from a Harvard history professor," said Mr Tatchell.
"Far from being off the cuff, he has been making these pretty offensive observations for some time. While on the face of it his apology is nice to read, it is not entirely clear whether the motivation is genuine regret or convenient," added Mr Summerskill.
"If he takes the view, and it now emerges he has expressed it in print, that gay people cannot have a proper sense of economics or history, can he offer some assurances that this has not affected his evaluation of students in the past?" he said.
The furore began on Thursday when Professor Ferguson was asked to react to Keynes's observation that "in the long run we are all dead" during a question and answer session. He suggested Keynes was indifferent to the long run because he had no children due to being gay.
In an "unqualified apology" on his website, he insisted the point he was trying to make was that in the long run our children, grandchildren and great-grandchildren are alive, and will have to deal with the consequences of our economic actions.
He continued: "But I should not have suggested – in an off-the-cuff response that was not part of my presentation – that Keynes was indifferent to the long run because he had no children, nor that he had no children because he was gay. This was doubly stupid. First, it is obvious that people who do not have children also care about future generations. Second, I had forgotten that Keynes's wife Lydia miscarried."
Professor Ferguson added: "My disagreements with Keynes's economic philosophy have never had anything to do with his sexual orientation.
"It is simply false to suggest, as I did, that his approach to economic policy was inspired by any aspect of his personal life. As those who know me and my work are well aware, I detest all prejudice, sexual or otherwise.
"My colleagues, students, and friends – straight and gay – have every right to be disappointed in me, as I am in myself. To them, and to everyone who heard my remarks at the conference or has read them since, I deeply and unreservedly apologize," he concluded. Professor Ferguson moved to Harvard in 2004 and was an adviser to the John McCain US presidential campaign in 2008. A right-wing commentator and critic of Barack Obama, he is married to the leading feminist and atheist activist Ayaan Hirsi Ali.
Keynes, who died in 1946, was one of the 20th century's most influential economists and philosophers. He is credited with challenging some of the key tenets of free market thinking.