A law change later will mean the Catholic Church will no longer be able to skip the usual hiring process for teachers.

Up until now, it could arbitrarily appoint nuns and priests to jobs in State schools.

Today, the Department of Education will alter the rules to ensure all roles are filled through open competition.

Shannon Parish Priest Father Tom Ryan said the current agreement was introduced just two years ago.

"My understanding is that the Articles of Management allow for this at the present moment," he said.

"These Articles were just agreed as late as 2015 between unions, between religious [representatives] and between the Department and between management. There's nothing unusual about it," he said.