The Irish Federation of University Teachers has said it is extremely disappointed by what it calls the behaviour of the Minister for Education Jan O'Sullivan.
It is understood O'Sullivan has cancelled her planned attendance at their annual delegate conference today.
The union, along with SIPTU, is involved in a dispute with University College Cork over pay parity for staff at the Tyndall research institute.
A number of days of pickets are taking place this month and her cancellation is said to be in connection with this row.
General Secretary of IFUT Mike Jennings has said Minister O'Sullivan's cancellation and the manner in which it has been carried out is disrespectful.
“We’re extremely disappointed with the behaviour of the Minster for Education, I think it has shown great disrespect and discourtesy,” said Jennings.
“The minister accepted our invitation months ago to attend and informed us by text yesterday that she wouldn’t be attending.”