More than 1,500 people have signed an online petition calling on the Welsh Government and Caerphilly County Borough Council to guarantee the long-term future of Cwmcarn High School.
The school was closed in October after contractors found asbestos and the school’s 930 pupils were later moved to the former Coleg Gwent campus in Ebbw Vale.
In a recent Christmas letter to parents published on the school’s website, headteacher Jacqui Peplinski urged parents to sign the petition.
She said: “We are delighted that the learners have been so positive about the move. I would like to take this opportunity to thank you for your support and trust in us at this difficult time.
“We are in the process of sending in independent experts to assess the situation in Cwmcarn and we will update you on the outcome as soon as we can.
“In the meantime, we will all look forward to our return to Cwmcarn High School in Cwmcarn; we are positive about the future. Please continue to follow developments on the school website and insist that everyone signs the petition.
“The Parent Support Group is a fantastic initiative and I am overwhelmed by the action that parents have initiated.”
Contractors Santia Asbestos Management Ltd said in its October report there was asbestos contamination in ceiling voids and recommended the demolition of affected buildings.
The findings of the report have been called into question after it emerged the contractors used a much lower threshold in recording asbestos.
Earlier this month a council-backed planned survey of the entire site was stopped after the school’s governors said they wanted their own independent survey.
The Health and Safety Executive is also carrying out its own investigation.