COTU has given tea multinational companies seven days to start negotiating the CBA it agreed on with workers or face a strike.
Secretary General Francis Atwoli said the entities only implemented 30 per cent of the 2014-2015 CBA.
The MNCs in Kericho, Sotik, and Nandi moved to the court of appeal to annul the remaining 15 per cent.
COTU has more than 100,000 members in tea growing zones in the larger Rift Valley region.
Atwoli on Wednesday said there is an existing court order compelling the Labour Commissioner to convene a meeting to discuss the two CBAs.
He said this during a press conference attended by national officials of the Kenya Plantation and Agricultural Workers Union (KPAWU).
The COTU boss said he will personally lead the strike adding that the union will also push the multinationals to stop using tea picking machines.
He said the machines have rendered hundreds of residents of tea growing areas jobless.
"The strike will be costly for the multinational tea companies."
"The labour commissioner was to convene the meeting on Friday. If this fails, all workers in tea plantations will strike," he said.
The union argued that the terms and conditions of services have remained constant for the past four years, despite the high cost of living and inflation.
Atwoli regretted that tea growing companies could not review workers' welfare without the intervention of unions adding that this contravenes labour laws.
"From an extensive research I carried a few months ago on the performance of the tea sector, I can confidently reveal that they are making huge profits."
"They (MNCs) are reluctant to pass it over to workers who toil in the farms," he said.
He supported Kericho Governor Paul Chepkwony's directive that multinationals which fail to withdraw tea picking machines will be denied trade licenses.
"We have information that some of the companies have threatened to use the machines or outsource labour to defeat the workers' demands," he said.
KPAWU deputy secretary general Thomas Kipkemboi said the parties were directed by the court to appear before it for hearing.
"Our union will not allow tea growers that include Unilever Tea Kenya Limited, James Finlay (Kenya) Ltd, the Kenya Tea Growers Association and Eastern Produce Kenya Ltd to continue exploiting workers."
Early this year, the union moved to court seeking orders to have the companies compelled to institute negotiations for the review of the CBA covering 2016-2017.
According to the CBA, the companies were expected to present a counter-offer to the union’s demand for 100 per cent salary increment.
The workers are also pushing for improved housing allowances.