Junior Education Minister John Halligan has been blasted for failing to find enough seats on school buses.
Despite admitting he is open to change, Mr Halligan said he must work this year within the existing guidelines.
More than 750 pupils missed out on school bus seats in 2016 and a similar number are expected to be disappointed by the time all schools reopen later this week.
Mr Halligan told the Herald he understood the frustration felt by families and said he is open to change.
He said he believed there was scope to review the distance a child must live from school before they are eligible for a seat and argued "a bit more compassion on pricing" should be shown to families on social welfare.
A primary school pupil must live 3.2km from their nearest school. For a post-primary pupil, it must be 4.8km.
When all qualifying children have been given a seat, Bus Eireann offers leftover seats to other applicants. These are known as "concessionary" places.
"I have as many complaints from Fine Gael backbenchers as Fianna Fail," said Mr Halligan.
"I can't go outside the parameters. When I was in opposition, I was the same. I'd be saying this is not right."
Independent TD Mattie McGrath is to meet Mr Halligan and a group of concerned parents from Tipperary today.
He said it was wrong that so many parents have learnt only in recent weeks that their children will not be given a concessionary seat and argued that Bus Eireann needed to provide bigger buses.
"It's very frustrating that families who have to work are being told they can't get a school bus," said Mr McGrath.
"It's a huge worry with kids going back to school.
"It comes down to the last hour and people could be on holidays or anything. This should have been done long ago."
He argued that bigger buses would not add a significant cost to the Department of Education.
"It would be the same driver expenses, the same diesel expenses and the same roads."
However, Bus Eireann said the school bus scheme is "heavily subsidised" and the rules state that larger buses cannot be provided to cater for concessionary passengers at an extra cost to the State.
It said the purpose of the scheme is "to support the transport to and from school of children who reside remote from their nearest school".
"Each year, after all eligible children are accommodated, any remaining seats may be made available on a concessionary basis subject to conditions governing this transport provision, which are set out in the guidelines of the School Transport Scheme.
"Under these guidelines, routes will not be extended or altered, additional vehicles will not be introduced."
Responding to criticism of the last-minute replies to many parents, Bus Eireann said: "We are currently issuing tickets for school transport places as late payments continue to be received and every effort is made to accommodate as many concessionary applicants as possible, where capacity allows."