Ten special needs assistant posts have been cut from three secondary schools in Sligo.
Four have gone from Summerhill College, three from the Mercy College and three from Ballinode College.
Senator Marc MacSharry said Education Minister Jan O'Sullivan has failed to give any clear explanation as to why this has happened.
Sen MacSharry said: "I am concerned about the savage cuts to SNA posts in County Sligo compared to other counties.
"Nearly a third of post-primary SNA posts in County Sligo have been cut while other counties have recorded increases in classroom support."
There has been criticism of the Minister after some special needs assistant posts were advertised under the JobBridge scheme.
"The Minister needs to explain why SNA posts have been advertised under this scheme when it requires there be a possibility of paid employment after the nine month placement.
"This is effectively dumbing down our education system and undermining the valuable role of SNAs in our schools," he said.
Sligo is one of six counties which has suffered cuts to SNA posts this year. Of the six, Sligo has suffered the most, the loss of ten posts.
These are divided between Ballinode College (Six posts reduced to three), Summerhill College (Eight cut to four) and Mercy College the losss of three posts.
There were no other cuts in allocation in any of the other ten post primary schools in the county.