Transparency International Zambia has observed with concern the silence by the opposition over the draft constitution released last month by the technical committee.
TIZ executive director Goodwell Lungu says political parties should start engaging their members on the contentious issues in the draft constitution.
Mr. Lungu says it very important that the first draft constitution does not go to the next stage without the participation of opposition political parties.
He says political parties should not cry foul when the document brings out clauses that do not seem to be in their favour.
Mr. Lungu has further revealed that as civil society organizations, they will not allow the draft constitution to be politically manipulated as has been the case in the past.
He says the civil society organizations in Zambia will ensure that progressive clauses are enshrined in the final constitution for the benefit of Zambians.
Mr Lungu was speaking in an interview with QFM radio in Lusaka.