I had been talking to Shami Chakrabarti, the telegenic director of Liberty about her organisation's predecessor, the National Council for Civil Liberties, and the work it had done for Jews attacked by neo-Fascists immediately after the war, when she suddenly turned the conversation to contemporary antisemitism.
Legislation against race discrimination introduced in the 1970s had simply not been enough to curb deep-rooted anti-Jewish prejudice, she said.
"I have witnessed the prevalence of a casual antisemitism that troubles me and it is probably greater today than it even was at times in my youth," she said.
Ms Chakrabarti, who grew up in north-west London as the daughter of immigrants from Calcutta, said her parents' Jewish friends had been a key influence on her during her youth.
But she had witnessed a worrying trend in recent years, especially on Israel. "I do think that sometimes it is because people are eliding, or think it is acceptable to elide, the criticism of Israeli government policy with peoples' race. And I have heard it done, and it turns my stomach.
"It's when, for example, the word Zionist is used in some parts of political debate, but not used in a political sense. It is not used to mean someone who believes in the State of Israel for example, but you feel it's used euphemistically and pejoratively. Or it's when people make assumptions about somebody's politics because they are Jewish. Or they make assumptions about how somebody will feel about some of the issues I work on, like anti-terror policy, because of their race. I have seen it, I have heard it, I have watched it - and it makes me incredibly uncomfortable."
Her comments mirror those made by the Conservative Baroness Warsi, who had witnessed a growing dinner-party Islamophobia.
"When, for example, centre-left liberal British Jews are feeling uncomfortable amongst their friends because assumptions are being made about their politics or their views on the Middle East, that's not a good thing. It's not my job to comment on what the government of Israel does. But what is definitely wrong is to make an automatic association between what any government does and what a group of people do all over the world."
I met her in her basement office at Liberty's admirably shabby offices near London Bridge. The last time I was there it was to meet the Iraq war whistleblower Katherine Gun, who had revealed details of a US-led spying operation at the UN. Liberty is an organisation which defends the rights of those who speak out against state abuses.
This is why its director had found herself in hot water when it was revealed that the council of the LSE, on which she sits, had authorised a donation from Saif al-Islam, the son of Libya's Colonel Gaddafi.
She stood by her decision not to resign from the council, explaining she had not been in the meeting where the decision was made and raised her concerns as soon as she heard about it.
"Whilst I regret that I couldn't attend the crucial meeting and could only raise my objections afterwards, it would be disproportionate to walk out now," she said. "As a result of this row, universities around the country will start having the debate, not just case by case, but on a more rounded basis… Frankly we should be having this debate in industry and government as well. What kind of engagement is acceptable?"
I explained that many JC readers were suspicious of the LSE, because of anti-Israel activism on campus, which had come to a head at a meeting in December entitled: "How much influence does the Zionist lobby exert in the US and UK?"
She said debate, sometimes heated, was an important part of the culture of the LSE, but added: "I was born and brought up in northwest London. I lived in a bedsit in Golders Green when I went to the LSE. Some of my strongest influences, including human rights influences, have come from the north west London Jewish community. If I had any credible evidence that Jewish students were unhappy or feeling oppressed at the LSE, I would be acting on it."
She recognised that some British Jews had become alienated from the human rights cause, but emphasised that much of the international law on the subject had grown out of the experience of the Jewish people during the second world war.
"Let's be absolutely clear: the universal declaration, human rights legislation and, I would argue, the refugee legislation in particular, this is the world's apology to the Jewish people for the Holocaust."
She said she was opposed in principle to an academic boycott of Israel, but did not feel she had the expertise to comment on the wider politics.
But where it did touch on domestic politics, such as universal jurisdiction, she felt the coalition's proposals to give the Director of Public Prosecutions a veto over the issuing of arrest warrants went too far.
Instead, she thought it would be better to put the DPP on notice every time a private prosecution was brought or an arrest warrant sought for an alleged war crime.
"I know that people have particular concerns about people coming from Israel, but I think the fair way through this to meet people's concerns, even if they are not founded on lots and lots of warrants having been issued, is to say no warrants are to be issued, and no private prosecutions brought, without notice to the DPP."