Led by James Dubai, John Mbarire and Joseph Kamande from Meru, Kirinyaga and Murang'a counties, the farmers said the senator should not play politics with the issue.
In a meeting at Kenol market, in Kandara, the farmers said the senator was playing politics when he should be championing the interests of the farmers.
They criticised the senator over claims that private coffee brokers Peter Githinji and Roselyn Chepkurui should not be in the technical committee due to conflict of interest.
Murango this week repeated that the duo were directors of privately-owned Alliance Berries Limited yet the committee lacks representation from counties that produce coffee in large quantities.
Murango, who also chairs the Senate Agriculture Committee, said the farmers invested in building the Nairobi Coffee Exchange and would not allow the transition to the Coffee Exchange.
"We need the committee to have representation from Kirinyaga, Nyeri, Embu, Kericho, Murang'a, Bungoma and Meru counties. As it is, they are not represented. We will go to court to challenge the Gazette Notice that appointed the technical committee," said the senator.
Mbarire said those appointed to the committee are experts in the coffee market, and politics should not be entertained.
"Politicians should help formulate the policies to support the growth of the nation and stop mudslinging the experts. Chelugui (Cooperative CS Simon Chelugui) appointed individuals with knowledge to help in the transition," said Mbarire who hails from Kiamugumo village in Kirinyaga County.
Charity Nkirote, an estate farmer from Meru, called for more members to be incorporated in the committee.