Tyler Hamilton, whose testimony helped bring down Armstrong, also blasted McQuaid, saying the Irishman had “no place” in the sport.
McQuaid had described Hamilton and Floyd Landis, who also testified against Armstrong, as “scumbags” on Monday.
“Pat McQuaid’s comments expose the hypocrisy of his leadership and demonstrate why he is incapable of any meaningful change,” Hamilton wrote in a statement on Tuesday. “Instead of seizing an opportunity to instil hope for the next generation of cyclists, he continues to point fingers, shift blame and attack those who speak out, tactics that are no longer effective. Pat McQuaid has no place in cycling.”
Hamilton and Landis were among the 11 former Armstrong teammates that testified against him.
Armstrong, widely accepted as one of the greatest cyclists of all time, given he fought back from cancer to dominate the sport, has always denied doping and says he has never failed a doping test.