The union representing St John ambulance staff says the Government needs to clarify who qualifies as a "high-risk healthcare worker".
There are just 11 days to go until high-risk staff need to get their first COVID-19 vaccine or be stood down - but the Health Order still hasn't been released.
St John staff are used to working under pressure but some still don't know if they'll have a job at the end of the month.
"Obviously it's giving them a very small timeframe to be able to make some serious decisions about their career," First Union ambulance coordinator Faye McCann said.
High-risk health workers need to get their first vaccine dose by October 30 but eight days after announcing the mandate, the Government still hasn't specified who qualifies as "high risk".
"One of the constraints we've got is just that getting it down onto paper is taking a little while," COVID-19 Response Minister Chris Hipkins said. "There are also some technical issues that they're having to work through, so exactly where you draw the line is very important."
First Union says the Government needs to release the Heath Order as soon as possible.
"It's about supporting the people that are affected that haven't yet got their vaccination to understand the reason why they haven't got their vaccination and how we can help them either get the vaccination or understand their issues and where they could possibly be re-deployed to," McCann said.
The union says some St John staff had signed up for clinical trials of the Scottish-made Valneva vaccine due to start in January. They don't know if they'll be covered by the mandate - or if they'll be stood down.
"It certainly leaves them in a difficult position and it's quite unclear, especially with the vaccination order not coming out yet exactly what position it's gonna put them in," said McCann.
Hipkins doesn't know if they would be exempt either.
"We've built an Exemption Authority and I think in this case... that'd be a matter for an exemption process," he said.
In a statement, St John deputy chief executive of people and organisational strategy, Emma Butler, said all its staff have been strongly encouraged to get vaccinated.
"Over 90 percent of St John ambulance staff in patient-facing roles have received at least one dose of the COVID-19 vaccine, with the vast majority having already received their second. This figure is likely to have increased following Super Saturday.
"St John has not been made aware of any ambulance officers taking part in a vaccination trial."
Butler said St John will support its people to comply with the mandate requirements.
