Ireland’s education department did not trust anyone enough to warn them of the calculated grades problem, Labour has said.
Two computer coding errors left some 6,500 students with at least one grade lower than they should have received last month.
Political rivals believe the Government should have disclosed the flaw sooner.
Around 200 parents and students made contact with a new helpline on Wednesday, Minister Norma Foley told the Dail on Thursday evening.
Labour TD Aodhan O Riordain said: “Your department does not trust anyone.
“You do not trust your cabinet colleagues, you do not trust anyone in the educational sphere.
“No one knew this was coming.
“No one from the third level institutions or students’ union bodies nor teachers’ unions knew this was coming.
“So obviously the education department does not trust anyone, it certainly cannot tell us but you cannot tell anybody about what was coming.”
Calculated grades were introduced after exams were disrupted by the coronavirus shutdown.
The minister has apologised to students, saying the mistakes should not have happened.
She said that further checks are taking place to see if any further errors have occurred.
Mr O Riordain tempered his remarks in a personal tribute to the new minister.
“I believe you are a compassionate, capable politician who is going to deliver a lot of good change in the education system in the coming time.”
Ms Foley said many people had principled objections to how the calculation of grades was handled.
She said they would do their utmost to ensure students were in a position to receive their college place offers this year.
“It is not an ideal situation.
“I would never have wanted students to be in this position.
“All of us would only want the best for the students.”