About 170 roles at St John Ambulance are at risk as part of a major restructure.
The first aid charity said its “refreshed community first aid-focused strategy” would affect about 10 per cent of its 1,700 employees.
SJA said it was changing its approach in response to a post-pandemic downturn in revenue due to lower demand for workplace first aid training courses.
The courses provided its primary source of income, the charity said.
A St John Ambulance spokesperson said: “St John is a people-oriented charity, and while our transformation will mean changes for some of our people, we will seek to minimise the impact as much as possible, including through considering wider changes to our ways of working.
“Ultimately, a community-focused St John, that reflects our founding mission, and builds on our heritage, will help us continue to save lives, grow the resilience of communities, create opportunities for individuals of all ages to develop and help reduce demand on frontline health services at a time of unprecedented pressure.
“We believe that making changes now will help us maximise that positive impact in society in the years to come.”
The charity said the updated structure would have to continue for the “medium term” because it was unclear when its income would return to pre-pandemic strength.
A spokesperson said many of the changes would be implemented before the end of the year.
The charity told Third Sector: “We are doing everything we can to support colleagues at this unsettling time and we are engaging widely with them to inform our approach and help shape the future of the charity.
“Through people moving on in the normal course of their career, those seeking voluntary release and retraining people, we hope that our transformation programme will negatively impact as few people as possible.
“We will also continue to take wider mitigating measures to help us reduce costs – through ways of working, reducing waste and considering changes to help us become more efficient in the long term.”
St John Ambulance has been teaching and providing first aid and emergency medical services since 1877 and operates across the globe.