Wabba also said the policy was in violation of the rules and procedure in service.
Okorocha declared Thursday and Friday as farming days for civil servants in the state as part of his Back To Land For Agriculture program.
The NLC President, Ayuba Wabba said the move by the Governor goes against the International Labour Organisation Convention.
He accused Okorocha of forcefully sending trained civil servants to the farm against their will.
Waba also described as criminal, the passage of the framing policy into law by the state House of Assembly without due consultation.
The Governor of Benue state, Samuel Ortom, in June 2016, declared that every Friday will be a work free farming day for civil servants.
The NLC President also added that while other states are asking civil servants to farm voluntarily, Okorocha has made it a policy.
Wabba, who said Nigeria is part of the treaty prohibiting forced labour, said what the Imo Governor is doing can be likened to it.
He said “How can you, for instance, ask a teacher not to go to school to teach pupils for two days a week? Or a health practitioner be given a particular date as disease doesn’t give a notice?
“You don’t give notice before you fall sick. So at the time when you are going to farm, an epidemic can actually come up; how you can address all of these?
“Or you want to put two standards in place; you ask one category of workers to come to work three days a week and another category to go to farm.
“That is not done; there are better ways to do that; he can encourage farmers; he can allocate lands and give them fertiliser and give them other incentives.
“You can put laws in place and encourage workers to go into farming; but not through a very cruel process of working against the law and forcing them to go to farm which is against our law and against our convention.’’
Experts say the back to farm programs initiated by most state governments is aimed at diversifying their economy and empowering their people to cushion the effect of the current economic challenges in Nigeria.
The Imo Governor also advised youth corps members in the state to establish farm and agricultural extension centres to strengthen government efforts at boosting food production.
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