Mick Whelan, boss of train drivers’ union Aslef, blasted government plans to bring in agency staff to replace those taking industrial action.
MPs moved to hit out at the emotive language used to describe a strike-breaker – someone who works despite picket lines being lined up.
Mr Whelan told the Transport select committee this week: “The real problem in an industry like ours – there’s still people not being spoken to who scabbed in 1955, in 1982.
“Of course scab labour can only work for scab management.”
But committee chair Huw Merriman said: “If any reasonable person heard what you said, when you used the term ‘scab’ about four or five times, I would take it as quite intimidatory.”
Transport Secretary Grant Shapps vowed to allow agency staff to carry out services last month.
Aslef train drivers will go on strike on Saturday, July 30, disrupting travel to the Commonwealth Games. RMT rail staff members have announced more strikes for July 27, August 18 and August 20.