Hundreds of primary teachers are to be retrained for secondary schools to help solve staff shortages.
There are problems recruiting teachers for key subjects like Irish, European languages, chemistry and physics, according to the Irish Times.
The situation is getting worse as pupils numbers rise, with a record 400,000 students expected to be enrolled by the year 2024.
The Department of Education is also looking at potentially sharing workers between schools, training native language speakers to take classes and offering financial incentives for teacher training to encourage more people into the profession.
The ASTI has welcomed the plans. Its Assistant Genereral Secretary Moira Leyden says primary teachers will be well able to make the change.
"Primary school teachers have to do a bachelor of education so yes, they have the knowledge base.