In the letter, which is also addressed to the Director General of the Migration Agency, the staff at the immigration service for the western region, express their frustration with management, who they say could do more to ease the workload, which has left them on their knees.
The employees say they can no longer plan anything in their private lives and that they feel stressed out and tired.
"We have worked late nights and weekends, often more than 14 hours straight," the letter says. They write that they have been flexible and done all they can to help the asylum seekers and refugees who have come to Sweden.
One employee, interviewed by Swedish Radio's local channel in Gothenburg channel, and who wants to remain anonymous, says he and his colleagues recently found out that they have to work over Christmas and New Year, a time they were looking forward to for a break from the chaos. The amount of people going off sick, they say, has increased.
The staff say in the letter that they understand the Migration Agency is under strain, with so many people arriving in the country, but even so, they say that they have received no information from management about any changes in work routines.