Henderson, who told the Mail he served in the Royal Corps of Signals, 32 Signal Regiment in Northern Ireland, said he managed to get up and walk out of the station.
“I’ve never known anything like it,” he said.
“Singing. Saying that everything has to do with the British government, the British people and the Jews.”
It comes as Scotland Yard on Monday pleaded with organizers of a pro-Palestinian march planned for Armistice Day to cancel the rally amid growing fears of violence.
More than 70,000 people will attend the rally in London on Saturday to protest against the Israeli bombing of Gaza, the same day veterans plan to gather at the Cenotaph.