Humza Yousaf must reverse planned cuts to the number of beds at Ayr University Hospital.
Scottish Conservative MSP Sharon Dowey demanded that the government acts after it emerged that two dozen beds could be removed and a ward may be closed.
The South of Scotland representative said the SNP Government must intervene and reverse this planned cut to bed numbers.
She also accused Mr Yousaf of “breaking his word to the people of Ayrshire”. In a letter to Ms Dowey, the health secretary had promised to maintain services at Ayrshire hospitals.
NHS Ayrshire and Arran have confirmed there will be a “reduction” in beds but did not say how many would be cut.
Reports say that up to 76 beds may be removed.
Scottish Conservative MSP for South Scotland, Sharon Dowey, said:
“Reducing the number of hospital beds for patients is a disgrace, especially when our NHS is already in crisis.
“Humza Yousaf has been caught breaking his word to the people of Ayrshire. He personally promised me that local health services would not be reduced but it looks like he is too busy with his leadership bid to support our NHS.
“Cutting the number of beds and closing a ward is unacceptable.
“The SNP Government must intervene and reverse this decision. People across Ayrshire deserve to know there will be a hospital bed available if they need it.”