The Employment and Labour Relations Court on Friday declared the nurses' strike illegal.
Lady Justice Hellen Wasilwa thus directed the Kenya National Union of Nurses (Knun) officials to immediately call off the strike and desist from interfering with the smooth running of health care services through declaration of illegal strikes.
The nurses first went on strike on December 5 last year seeking the harmonisation of their Collective Bargaining Agreement (CBA).
The strike lasted a few days and on December 14, a negotiated return-to-work agreement was signed by their officials.
Justice Wasilwa said that the strike was unlawful because Knun did not issue a strike notice to the Cabinet secretaries for Health and Labour as provided for under the Labour laws.
She said the strike notice issued on November 2016 cannot be used to effect the strike, which commenced on June 5, 2017.
Knun had claimed that they had issued a notice last November and that it had only been suspended.
"According to the consent between Knun and the government, the whole matter was marked as settled.
"It cannot therefore be alleged that the strike notice issued in November last year is the same one that can be used to call a new strike in June," Justice Wasilwa said.
On Thursday, governors ordered nurses to resume work by September 8 or face the sack.
The order puts over 25,000 nurses in a tight spot.
Justice Wasilwa noted that Knun national chairman John Biiy was not involved in the union's executive committee, which called the strike.
The court said that being the chairman, he ought to be involved.
The judge thus directed that Mr Biiy be reinstated in the negotiation team of the CBA involving Knun, the Ministry of Health, and the Council of Governors (CoG).
The application had been filed by Mr Biiy through lawyer Elijah Bitange Mageto, arguing that the union's Secretary-General Seth Panyako had, without any consultation, committee resolution or notifying the national chairman, called for a strike on the grounds of failure by the Ministry and Council of Governors to sign a proposed draft CBA.
"Without issuing a mandatory strike notice to the ministry and CoG, Mr Panyako called the strike and left the country for International Labour Organisation meeting in Geneva, Switzerland, after illegally purporting to appoint Ms Ido to act as the Knun general secretary," Mr Mageto had told the court.
Mr Biiy was also aggrieved that other union officials called for the strike yet negotiations were ongoing.
The Ministry of Health threw its weight behind Mr Biiy's application seeking to have the strike called off.
Principal Secretary Julius Korir in court papers said that the industrial action called by the officials was premature because talks were in progress.
Governors on Thursday said they will not hesitate to hire new personnel on a contract basis if the current group defies the directive.
The PS said that any action jeopardizing conclusion of the same must be discouraged at the earliest opportunity.
The Salaries and Remuneration Commission (SRC), whose advice is constantly sought by the parties, had on June 9, through a letter, advised on the parameters within which the CBA can be negotiated and urgently concluded.
"The orders sought and specifically the one seeking the calling off of the strike by Knun members is meant to safeguard public interest in the Health Sector and avert further suffering by Kenyans, as a result of the strike," Mr Korir had said in court papers.