Requiring Sydney's Catholic school leaders to take an oath of fidelity to adhere to church teachings on homosexuality, birth control and women's ordination is not discriminatory, the NSW/ACT Independent Education Union (IEU) says.

Principals, deputy principals and religious education coordinators at more than 120 Catholic primary and 40 Catholic secondary schools in Sydney will most likely have to take the oath in early 2008.

The requirement is one of many initiatives of the draft Archdiocese of Sydney Pastoral Plan 2008-2011 to advance Catholic initiatives in schools and the church.

The Archbishop of Sydney, Cardinal George Pell, is behind the move to extend the oath - which is a requirement of church law for bishops, priests and heads of seminaries - to all senior educational leaders.