Liberal Judaism chairman Lucian Hudson has said Reform rabbi Laura Janner-Klausner was wrong not to attend the funeral of Baroness Thatcher.
Rabbi Janner-Klausner said that she could not honour the former Prime Minister because she had been "a cataclysm for the fabric of Britain".
Reform was represented at the service at St Paul's Cathedral by the chairman of its rabbinic assembly, Rabbi Mark Goldsmith.
Mr Hudson said: "While we hold Laura in respect, we don't agree with the stance she took in declining the invitation and the reasons she gave for it. Lady Thatcher was a friend of the Jewish people and of Israel. If Liberal Judaism had received such an invitation, we would have accepted it."
Reform chairman Jenny Pizer attempted to play down controversy this week, saying that the movement had "kept to established protocol" in sending a representative to last week's funeral.
"Our president, Rabbi Dr [Tony] Bayfield was not available and the chair of the Assembly of Reform Rabbis, Rabbi Goldsmith, represented us," she said.
The JC understands that Reform were invited in a phone call from St Paul's to send a representative to the funeral and asked to respond within a quarter of an hour. Rabbi Bayfield could not be reached in time. As Rabbi Janner-Klausner, who holds the title of movement rabbi, did not wish to attend, Rabbi Goldsmith agreed to represent Reform.
He said: "Our movement rabbi is not a chief rabbi-substitute. She is not our only public face to the world. Part of her role is to enable all of us to be more outward-facing rabbis."