RMT officials said the Trump Organisation is using the pandemic as a “shameless” guise to cut terms and conditions for workers.
The union said more than 80 posts face being made redundant at the resort now that a consultation period is over, with reductions in sick pay and working conditions also expected.
Nicola Sturgeon said she is not aware of the issues at Trump Turnberry but said all businesses should be responsible to their workforces.
Calling for action to stop the “savage” cuts, the RMT has written to the First Minister, saying the Trump Organisation “is shamelessly using the global pandemic as a guise for slashing terms and conditions of workers in Scotland”.
RMT senior assistant general secretary Mick Lynch said: “It has been clear from the outset that the company is hell-bent on cutting jobs and slashing terms and conditions, under the guise of Covid-19, while at the same time as being in receipt of British taxpayers’ money in the form of furlough payments.
“It is disgraceful that the Trump Organisation is ploughing ahead with these outrageous cuts, when it is clear that the real goal is casualising the workforce, with no regard for its dedicated employees.”
A Scottish Government spokeswoman said: “We are very concerned about the proposed redundancies at Trump Turnberry resort.
“We are monitoring developments at Turnberry and stand ready to assist any staff affected.”
The Trump Organisation was approached for comment.