Canberra's public schools are clawing back enrolments from the non-government sector at a rate almost three times the national average after years of fightback against private high schools who once boasted the majority share.
More than 60 per cent of all ACT students were enrolled in a government school in February this year with the remaining split almost evenly between the Catholic and independent systems.
In high schools, 51.7 per cent of students were in the public system and about 48 per cent in the non-government sector. Private schools educated more than half the ACT's secondary students between 2011 and 2014 but the public system won a slight majority in 2015.
The Association of Independent Schools of the ACT said minimal growth in non-government schools - 3.23 per cent since 2013 and .59 per cent between February 2016 and the same time this year - is evidence of schools nearing or reaching capacity.
Overall public school enrolments grew by 13.8 per cent in the past five years and 3.85 per cent since 2016.
University of Canberra education policy researcher Louise Watson said it was impossible to pinpoint why government schools were gaining ground on their non-government counterparts but noted it was indicative of a national trend.
The 2016 national data from the Australian Bureau of Statistics showed government schools had 65.4 per cent of the enrolment share, followed by Catholic schools (20.2 per cent) and independents (14.4 per cent).
Professor Watson listed the Royal Commission into Institutional Responses to Child Sexual Abuse, salaried wages being incompatible with high fees and transparent data about school outcomes on the My School website as potential reasons why parents were choosing the public system.
"The ACT rate of change is almost three times the national level," she said.
"Government school primary enrolments in the ACT have increased 23 per cent over the last five years, which is extraordinary.
"All schools have been operating in an environment of school choice for 10 or 20 years now and government schools are clearly attractive to parents."
Association of Independent Schools of the ACT executive director Andrew Wrigley said he did not believe the data meant parents were shifting from non-government schools. Canberra Christian School, for example, recorded a 42 per cent increase in enrolments.
"The data reflects a situation that has been emerging for the last few years: that is, while there are certainly some spaces available in some year groups in some schools, independent schools are generally running at close to capacity in terms of enrolments," he said.
"Anecdotally, waiting lists are healthy, and parents are keen to actively choose independent schools for their children for a wide variety of reasons."
Catholic Education Archdiocese of Canberra and Goulburn director Ross Fox said enrolments were largely driven by demographics and said he did not believe the Royal Commission had an impact on student numbers.
Fourteen out of 29 Catholic schools noted a decline in enrolments, including a drop of 14 per cent at Sts Peter and Paul Primary School, but the sector's newest ACT school, St John Paul II College, saw enrolments increase 34.6 per cent after introducing a Year 11 stream.
"The biggest issue for Catholic education and growth in enrolments in the ACT is accessing land for a school at Molonglo to service parents and families in growing areas of Canberra," Mr Fox said.
Gonski was funded by the Gillard Government