Mr 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 leave the station.
“I’ve never known anything like it,’ he said.
“Chanting. Saying it’s all about the British Government, British people, Jews.”
It comes as Scotland Yard on Monday pleaded with the organisers of a pro-Palestinian march planned for Armistice Day to call off the rally amid growing fears of violence.
More than 70,000 people are set to attend the demonstration in London on Saturday to protest against Israel’s bombardment of Gaza, on the same day as veterans plan to gather at the Cenotaph.