The GTA/NASUWT is the latest local organisation to declare its support for the Stronger in Europe campaign.
“We urge our members to vote IN at the EU referendum on the 23rd June,” the teachers union said.
“We are extremely concerned with the negative implications that a Brexit vote could have on the very fabric of life that we enjoy in Gibraltar and the effects that an out vote would have on worker’s right, infrastructure, financial security and especially education.”
The union said it would use its internal mechanisms to disseminate information and ensure that members understand the need to come out and vote.
It believes that this will send the UK and EU a clear message on where Gibraltar stands, “making us stronger regardless of the final outcome”.