Proposals by campaigners to save St Joseph's Primary in Milngavie are to be submitted to the consultation by East Dunbartonshire Council over plans for a merger with neighbouring St Andrew's Primary in Bearsden.
Parents argue the council's proposal will effectively end Catholic education in the area - and the Archdiocese of Glasgow also backs keeping the two schools as separate primaries.
Yesterday, a church representative said: "The Archdiocese of Glasgow will respond formally to the consultation, restating its firm support for the retention of St Joseph's Milngavie and St Andrew's Bearsden as free-standing primary schools serving their respective communities.
"Any proposal which effectively ends the provision of Catholic education in the Milngavie area, where there is a growing population of Catholic children, who are currently attending St Joseph's Primary School, would be unacceptable."
East Dunbartonshire says it is not closing St Joseph's but that the schools will operate on a shared campus on the site of St Andrew's. Although parents argue St Joseph's is the fastest-growing school in the local authority, with rolls up 26.6%, it is, according to the council, less than half full.
The paper on options to keep St Joseph's in Milngavie was drafted by Paula Speirs, a management consultant. It explores two alternatives, a shared campus in the town or a community hub offering a variety of enhanced facilities as well as retaining the primary school.
Laureen McIntyre, chair of St Joseph's Parent Council, said: "We want to stay where we belong.
"We were very disappointed when the council ignored Archbishop Tartaglia's personal plea earlier this year for them to bring forward alternatives to closure, but we have used the time over the summer to do the job ourselves.
"East Dunbartonshire Council has been forced to admit that a shared campus would produce savings of almost £100,000 a year. We believe that they could actually be much greater if officials looked at the issue with more imagination."
The council's head of education, Gordon Currie, said it remained committed to high-quality denominational schools.
He added: "While having a shared campus may suit some councils' circumstances, we do not believe, in this instance, that it is suitable."