Bus Éireann has written to private operators working under the School Transport Scheme to advise them that payments due tomorrow may be delayed.
Bus Éireann currently relies on a number of private operators to provide a rural bus service under the scheme.
These drivers have been notified that their payments will be delayed as a result of the week-long industrial action.
Drivers were reluctant to be identified but said some operators may be forced to withdraw from the scheme as early as Monday should they not receive their payments.
Brian Connolly, a regional manager with Bus Éireann, said the delay is due to administrative staff being on strike and said payments would be made next week.
Meanwhile, the Director of the Coach Tourism and Transport Council of Ireland has said it is of significant concern to the 115,000 pupils who avail of the school transport scheme that services may be curtailed as the strike continues.
Bus Éireann currently relies on a number of private operators to provide around 89% of services under the School Transport Scheme.
Kevin Traynor told RTÉ's Drivetime that drivers plan to fulfill their obligations to continue to provide the service, but concerns do exist.
Brian Connolly, a regional manager with Bus Éireann told the programme that the delay is due to administrative staff being on strike and said payments would be processed later next week.
There are also growing concerns on the impact of the strike on third-level students who are sitting exams in three weeks.
Councillor Martina Kinane from the Oranmore area on the outskirts of Galway said many students at NUI Galway and GMIT are unable to afford accommodation in the city centre and are struggling to attend their lectures.
She said the impact on their college work was totally unacceptable.
Meanwhile, Minister for Transport Shane Ross has again been criticised for not intervening in the dispute.
During Leaders' Questions in the Dáil, Sinn Féin deputy leader Mary Lou McDonald accused Mr Ross of "presiding over transport grinding to a halt".
She told Minister for Education and Skills Richard Bruton that it was as if Mr Ross had "found the entrance to Narnia and only pops out of the wardrobe every now and then".
Mr Bruton defended Mr Ross, saying he was doing his job.
He said the minister had negotiated improved input into the free travel scheme and was providing a future for the services provided by Bus Éireann.
But he said it was not open to Mr Ross to provide subvention to the commercial services provided by Bus Éireann.
He told Ms McDonald that if they sought ministers to come in with a chequebook to solve every dispute, there would never be a proper system of industrial relations.
He said it was very regrettable the dispute was causing so much hardship, but it had to be resolved by the Workplace Relations Commission.