The outspoken parliamentarian made her remarks after a year in which she was targeted for deselection by hard-left activists in her local party and narrowly lost a no-confidence vote against her in September.
But Ms Ryan insisted: "In this fight against antisemitism, I will never cower in the face of hatred and abuse. However long it takes, whatever the personal cost.”
Earlier, LFI Director Jennifer Gerber welcomed guests and supporters, including Chief Rabbi Ephraim Mirvis, Israel’s ambassador to the UK Mark Regev, Sir David Gerrard, Issac Kaye and new Jewish Agency chair Isaac Herzog, to what she said was the largest fund-raising dinner for a decade
More than 300 people attended, including 70 MPs and 30 peers.
Long-standing parliamentary supporters also attended, including deputy Labour leader Tom Watson, MPs Ruth Smeeth, Ian Austin, Dame Margaret Hodge and Luciana Berger, alongside LFI Lords chair Baroness Ramsay.
There was sustained applause for Dame Louise Ellman who was handed the LFI Lifetime Achievement award for her support for the group by Mr Regev.
Later in his speech, Mr Herzog, formerly of the Israeli Labour Party, attacked Mr Corbyn for the breakdown in relations between the British and Israeli party’s.
Shadow Foreign Secretary Emily Thornberry was also at the lunchtime event.
