Manjinder Shergill told families plans to close St Joseph's Primary School in Milngavie resulted partly from the Scottish Government's council-tax freeze and the resulting squeeze on public funds.
He also appeared to cast doubt on correspondence from families, with a "pattern" of residents claiming to have lived in Milngavie for five years with two children ready for school in the next few years.
"If this was the case for each resident who wrote this then there would have been a large number of houses in Milngavie sold to those wanting to access Catholic education five years ago, all ten minutes from the school, and all have two children of the same sex and age," he said.
"If this was true it would have shown up in the census or have been highlighted by the General Register Office of Scotland. Sadly it wasn't."
Mr Shergill questioned Catholic Church opposition to the closure, suggesting it was "playing politics" and pointing to rationalisation of the church's parishes which he said was being done without public consultation.
A spokesman for the Archdiocese of Glasgow said the email was a bid to justify the closure of St Joseph's and "drive a wedge between parents and the Church".
He said: "The truth is that the Archdiocese and the overwhelming majority of parents are united in opposing the closure of St Joseph's which is a successful and popular school. Its loss would represent the end of Catholic education in the Milngavie area.
"The reference to the consultation on future parish provision is not relevant … The Church has a responsibility to ensure good pastoral provision … but it also has a statutory right and duty to comment on the provision of Catholic education."
The spokesman said the Church wanted to "engage constructively" with the council to ensure the continuation of Catholic education in Milngavie and the email was "not helpful" .
Pam Hughes, who has a son at the school, got an email from Mr Shergill and was shocked by its tone. "Instead of a local education, the council is offering children a bus pass," she said.
"Parents, pupils, teachers and the Church have all asked the council to bring forward alternative proposals and it is time for them to listen.This sort of email makes me worry that their real agenda is to downgrade Catholic education."
East Dunbartonshire Council is expected to come to a decision on the closure at a meeting on Thursday.
Mr Shergill was unavailable for comment.