Bob Crow denied that the unions' objectives was undermined by his high profile and stressed that his holiday was "booked up well before" the strike action by thousands of London Underground workers that is set to go ahead this week.
Reports have emerged that ahead of the strike he recently enjoyed a £10,000 holiday in Brazil.
"If I'm going to spend £10,000 on a car, or if I'm going to spend £10,000 on a holiday, or £10,000 on cigarettes, that's up to me," said Crow.
"I'm not being a distraction at all. What do you want me to do? Sit under a tree and read books of Karl Marx every day?" he added.