The Good Morning Britain host and financial journalist was moved to recount the event after watching David Baddiel's new Channel 4 documentary Jews Don’t Count, recalling how he stood up to football fans mocking the Holocaust.
Lewis said: "Watching @Baddiel Jews Don't Count. Remembering sitting on a train in about 03 with a group the other side of the carriage, on their way to football doing gas chamber songs. I asked em to stop, most did & were embarrassed.
"One came up, asked me if I was 'a f***ing y*d' poking me in the forehead hard with each word. I was petrified but said yes. He then called me names & eventually walked away.
"What upset me most was no one near, not even the man reading the medical textbook would make eye contact after, as if I'd been the one in the wrong... He was opposite me, he could've given me a supportive glance after I'd been assaulted without anyone seeing but he didn't."
The TV presenter has previously revealed that he was given an antisemitic nickname at school.
He told BBC’s Political Thinking: “My nickname at school was ‘Jew’. There were two Jews in the year and my nickname was ‘Jew’. And it had originally had been ‘Jewy Lewy’ or something warmer, but it was shortened.”
Lewis added: “As I always say, I’m the Money Saving Expert and I'm Jewish – I’m not the Money Saving Expert because I'm Jewish.”
The 50-year-old TV star rose to fame after founding the website MoneySavingExpert.com in 2003 and is a regular guest commentator on ITV's This Morning and GMB.
Comedian Baddiel argues in his new documentary that antisemitism is equivalent to racism directed at the Jewish community.
He also apologises to footballer Jason Lee for donning blackface to impersonate him 25 years ago.
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