Kenya's government has sacked some 25,000 striking nurses for failing to return to work.
Spokesman Alfred Mutua has appealed to "all qualified health professionals who are unemployed or retired" to report to public hospitals for jobs on Friday.
The public health workers, who are mainly nurses, have been on strike for four days demanding better pay, allowances and working conditions.
The unions have dismissed the move as a negotiating tactic.
"These are cat-and-mouse games, you cannot sack an entire workforce. It is a ploy to get us to rush back to work, but our strike continues until our demands are met," Reuters news agency quotes Alex Orina, spokesman of the Kenya Health Professionals Society as saying.
He said that on average a health worker earns about 25,000 Kenyan shillings ($300, £190) a month in salary and allowances.
But Mr Mutua said the health workers were being "unethical" by not returning to their duties.
He said their names had been removed from the payroll and they were "no longer employees of the government".
Dr Victor Ng'ani, chairman of the Kenya Medical Practitioners, Pharmacists and Dentists Union, said it was a "reckless" decision.
He told the BBC it would be difficult to replace people with many years of experience and specialised skills.
Last week employees at Kenya's state broadcaster also downed tools.
The government threatened them with the sack and advertised their posts in the newspapers.
However the dispute was resolved and no jobs were lost.