Australian Marriage Equality campaign director, Rodney Croome, said it is "unAustralian" to sack staff because of views expressed outside work.
"Expressing a view on a mainstream issue in a social setting should not be the basis for depriving someone of their livelihood", Mr Croome said.
"Australian employees should not be looking over their shoulders every time they disagree with their employers."
A Seventh Day Adventist Church school in Melbourne has sacked a language teacher, Keith Paulusse, for stating his support for marriage equality on facebook.
Church elder, Johnny Wong, defended the sacking by saying the church believes marriage is solely between a man and a woman.
The sacking follows last year’s dismissal of ordained clergyman, Rev Matt Glover, from Melbourne’s Lilydale Baptist Church for supporting marriage equality.
"Just as some religious figures have no right to impose their definition of marriage on the rest of society, so they have no right to punish those within their church who disagree with this definition", Mr Croome said.
For a report on the sacking of Mr Paulusse:
For a report on the sacking of Rev Glover:
For more information contact Rodney Croome on 0409 010 668.