Victorian schools have been put on standby to help students distressed by "hurtful campaign material" ahead of the postal vote on same-sex marriage. In a surprise move, Education Minister James Merlin wrote to every state primary and secondary school on Friday, requesting that they prepare to connect upset students to welfare staff and school nurses.

He also directed them to the controversial Safe Schools Program, Bully Stoppers and headspace.

"Sadly, there have already been reports of children and LGBTI families being targeted in hurtful campaign materials regarding marriage equality," Mr Merlino said.

"School staff need to be ready to provide affected students with wellbeing supports."

While Mr Merlino is a Catholic who supports gay marriage, the carefully-written letter did not advocate for a "yes" vote. Such a move would have been seen as political interference in schools. It comes as LGBTI agencies prepare for a sharp rise in calls for help sparked by the same-sex marriage postal survey. Micah Scott, the chief executive of LGBTI youth group Minus 18, said calls to the service had doubled in the past month. Read more via The Age