Proposals to close scores of primary schools in Northern Ireland must not be used as a crude cost-cutting exercise, the region's largest teaching union has warned.
Concerns about job losses and excessive workload should be addressed in the shake-up, said the NASUWT.
Plans published by the five education boards include proposals for some joint Catholic and state schools.
NASUWT general secretary Chris Keates said: "There is scope to avoid closure, minimise disruption to pupils and maximise job retention by exploring the options for schools to work together and share resources in clusters or federations."
The proposals are dependent on the outcome of a public consultation and need final approval from education minister John O'Dowd. Some of the 846 schools risk closure because they have spent too much money, have too few pupils or are not up to standard.
Ms Keates said: "Handled correctly, these proposals present a real opportunity to enhance educational provision. Handled badly, they will generate a chaotic free-for-all and the workforce and children and young people will be the casualties."
She added: "Employers and the Assembly must take note that the NASUWT will not accept the proposals being used as a crude cost-cutting exercise and will expect them to address seriously the concerns about job loss and excessive workload, which are being generated by the reorganisation plans."
Mr O'Dowd said the plans will inform wide-ranging discussion and dialogue at local level.
He added: "This is an opportunity for an informed and mature debate that will shape future primary education provision and help identify local solutions that will benefit all children and young people. I hope to hear innovative ideas, including the consideration of possible sharing of accommodation and resources."
The consultation will remain open until June 30.