In the judgment, published last month following a three-week hearing last year, employment tribunal judge Anthony Snelson said Mr Newmark’s evidence had been “false, preposterous, extraordinarily arrogant and disturbing”.
But speaking at a Manchester Jewish Representative Council meeting on Sunday, Mr Newmark hit back.
He said the tribunal’s finding that there could be no link between Jewish identity and support of Israel “cannot be left to stand”.
“That is a shocking and ignorant statement to make. It is something that will have to be followed up," he said.
“If a Jew is bullied or harassed in the work place or his trade union, and part of that bullying or harassment contains anti-Israel slogans, material or activity, then to take that forward to the judicial system is considered by this panel in their ruling as an attempt to usurp the British judicial process for political means – that’s something that is very, very wrong.”
Mr Newmark said the JLC “felt that it was right to provide whatever support, assistance and evidence” it could to Mr Fraser.
He added: “It wasn't just Ronnie, it was hundreds of Jewish members [who] felt there was an atmosphere of bullying and harassment. Many decided to leave their union.
“Ronnie Fraser is a modern-day hero in the fight against antisemitism. Ronnie decided to take this on. He was bullied, he was harassed, he was vilified inside his trade union.”