The Secretary-General of the Public Service Association, Mele 'Amanaki, said a six member committee, including herself, organised the petition.
Ms 'Amanaki, was a candidate in the last two general elections.
Matangi Tonga reported the petition had been posted online for in an effort to gather more signatures.
The call for impeachment was for 'Akilisi Pohiva and six of his ministers, namely Semisi Sika, Pohiva Tu'i'onetoa, Penisimani Fifita, Mateni Tapueluelu, Vuna Fa'otusia and Tu'i Uata.