Labour's Angela Rayner has addressed "the elephant in the room" during her speech to the Board of Deputies annual Chanukah reception, saying her invitation "wasn't universally popular."
In an address aimed at easing widespread concern over her invitation to Monday's event at the House of Lords, the shadow education secretary referred to how she wrote in 2015 that Norman Finklestein's book The Holocaust Industry - which accused American Jewish leaders of exploiting the memory of the Shoah - was "seminal".
The comments that resurfaced last week amid tension and argument over the Board's decision to invite her to speak.
Ms Rayner said: "Some years ago I wrote an article reflecting on my visit to Auschwitz intending to show solidarity with Jewish community over the Holocaust and modern antisemitism.
"It included a reference that I now deeply regret and I would certainly not use it again.
"I can only repeat how sorry that I am for that."
Ms Rayner attacked the "horrifying consequences" of "bigotry about Israel and Jewish people generally," insisting that her role on Jeremy Corbyn's front bench had made her reflect on what she still had to learn.
She said Labour "could not rest as a party" until it too had rooted out Jew-hate from its own ranks.
Ms Rayner added: "I have seen the abuse my colleagues Luciana Berger, Ruth Smeeth, Dame Louise Ellman and Dame Margaret Hodge have received.
"I have no doubt the fact they are Jewish women has been a big part of that abuse."
Of the four Jewish Labour MPs that Ms Rayner mentioned, only Dame Louise attended the afternoon reception, although the event did coincide with the delivery of crucial Brexit statements to the Commons.
Ms Rayner insisted Labour had made "progress" with internal procedures on dealing with antisemitism, which was met with some scepticism at the Board event.
She said she was glad activists such as Tony Greenstein had been expelled and said "those who distort history by likening Hitler to Zionism are no longer welcome".
Ms Rayner said it was "perfectly possible" to criticise any government "Including Israel's" without resorting to "racism."
She said she was "glad" the Party had adapted the International Holocaust Remembrance Association definition of Jew-hate "with full examples".
She added: "I want to make it clear we will not stop faith schools including Jewish schools from maintaining their character and their ethos."
Earlier, Board President Marie van der Zyl defended her decision to invite Ms Rayner.
She said "attempts to engage are fraught with controversy and complexities" but added: "We have to communicate if we are to overcome challenges."
Lord Pickles also spoke at the celebration, after stepping in for Foreign Secretary Jeremy Hunt who withdrew because of the on-going Brexit debate.
Pointedly, Lord Pickles spoke of his involvement with as UK lead on the IHRA antisemitism definition.
He said he had "never intended to cause any problem to any political party in the UK" with the definition and that "initially everyone accepted it."
In a damning attack on those objecting to the IHRA's examples that illustrate how criticism of Israel can stray into antisemitism, Lord Pickles said the desire to attack the country as "an apartheid state" and "accuse Jews of dual loyalty" and other criticisms of the definition was "bigotry".
Lib Dem leader Sir Vince Cable also said it was "an honour" to address the event - especially after the brief introductory speech made by his colleague Lord Palmer.
He compared Chanukah commemorations with the "human wish to emerge from the darkest point of the year to something more positive and optimistic."
He added: "I know there is deep concern here about the way antisemitism has resurfaced or surfaced in a particularly pernicious way over the past year or two."
Chief Rabbi Ephraim Mirvis lit the Chanukah candles on the Menorah before the choir from Clore Tikva Primary School performed Maoz Tsur.
Guests at the event included Lord Dubbs, Labour's Jes Philips and John Mann, Lord Levy and Jewish Labour Movement chair Ivor Caplin.
