Patients requiring medical help will likely be greeted by ambulance officers in mufti today.

Nearly 1000 of First Union's St John members in the North Island are wearing union badges and going casual today as a way to protest without putting any lives at risk.

It follows failed mediations on Wednesday.

Spokesperson Lynette Blacklaws said St John has already reacted and threatened disciplinary measures on staff which is good because it means they're getting a reaction and being heard.

But she said it's also disappointing.

"It's quite appalling that St John is behaving like this, all their staff are doing is taking low level action, we're not putting anyone's safety in jeopardy."

Ms Blacklaws said they want St John to stand up to the government to get more funding so they can stop working 14 hour shifts with no breaks.

She said it reflected issues being heard elsewhere in the health sector, with junior doctors complaining of long hours with few breaks due to a lack of funding for District Health Boards.

"They aren't asking for much and their hands are tied as to how much they can do and so the uniform ban is just a way to say look here we are, we've got a message for you and you need to start listening".

She said if there are no changes they may have to consider further action such as a paperwork ban.

She said that would make it difficult for St John to bill people, but wouldn't compromise patient safety.