He told the audience that as a gay man he found the prospect of boycotts of Israel “outrageous” given the country’s prominence on LGBT rights.
A London Assembly member, he has previously told the JC of his concerns about extremism directed at Jewish students on university campuses.
But it is the candidacy of Ms Waters which has threatened to split the party. Ukip MEPs and other senior party figures have said they will resign en masse if she wins.
Ms Waters, who was banned by the party from standing as a Ukip candidate in the general election, is backed by Tommy Robinson, the former English Defence League leader who held a secret meeting with members of Manchester’s Jewish community last month. Together the pair formed the Pegida UK group which campaigns against Islam.
She also helped set up the Sharia Watch group which has previously publicised claims that halal food production in Britain could be used to fund Islamist terrorism.
Outlining her views on Ukip’s future direction, Ms Waters wrote last year: “Islam is as great a threat (if not greater) to British and European democracy even than the EU.”
Ahead of the Brexit referendum she wrote of “Ukip’s unique willingness to speak out against the poisonous suppression that is political correctness, or the racist obscenity known as multiculturalism”.
She is reportedly being advised by Jack Buckby, a former BNP member. On Monday, Mr Buckby wrote on Twitter that he and Ms Waters were “great friends”.
Ukip leadership outsider Jane Collins was forced to apologise three years ago after tweeting a link to an antisemitic blog which referred to Harriet Harman, the Labour politician, as a “Jewess”.
Another contender, David Kurten, a London Assembly member, visited the Knesset during a tour of Israel last December.
In total 11 candidates are standing in the party’s third leadership election in a year. It follows the resignation of Paul Nuttall after June’s general election. The new leader unveiled at the party’s conference in Torquay on September 29.
One Ukip source said Ms Waters was “very pro-Israel”, but warned that her potential victory would “put into context what a lid Nigel [Farage] kept on the party. Ukip is probably over anyway — she’ll just hasten it”.
