The Association of Secondary Teachers in Ireland (ASTI) has disputed figures that suggest that a third of their members have defied a ban on registering for Junior Cert reform training.
More than 5,000 members of the ASTI are registered for the training despite a union ban.
That is almost a third of their 18,000 strong membership.
However General Secretary of the ASTI, Kieran Christie, says there are a number of reasons why the figures may be skewed.
He said: "We would dispute those figures, many of the teachers you are discussing may have registered prior to the ASTI directive coming into effect in March 2014.
"Lots of schools have principals who are not members of the ASTI and may have registered teachers, so where that 5,000 number comes from is difficult to figure out."