When Labour last came to Brighton for its annual conference, I sat in a studio listening to people who had faced abuse because they were Jewish. I heard statements recorded at a fringe event suggesting it was fine to question whether the Holocaust had ever happened. As leader of the city's council, I had to act. I wrote a letter saying Labour would not be welcome back in Brighton if it failed to sort out its issues with anti-Semitism. Two years on, I have been forced out of the party I loved. But Labour's dark problem remains.
The backlash against my message was swift and took me by surprise. I had been a member of the party for a quarter of a century. Perhaps I was naïve, but Jeremy Corbyn's vow to root out racism made me feel I was helping.