"Giving extensions to incumbents in any institution creates perception of indispensability and weakens institutions. Transitions are important for institution building and creating viable institutions," said the statement.
It said the legislation process failed to address basic issue regarding the necessity and desirability of extending service of chiefs' terms in office.
The statement said, "Our history is replete with examples of the damage done by extending terms of powerful office-holders. In the third term of a democratic cycle, the mistakes of the past should not be repeated."
"The doctrine of necessity used to justify and legitimise extraordinary measures should have no place in a democratic dispensation," the statement added.
He called on all democratic organisations to endorse its stance in the greater national interest.
Human Rights Commission of Pakistan and AGHS Legal Aid Cell also endorsed the statement.
"We are also disappointed with political parties' response. "Instead of rushing into a discussion on the procedure for extending the army service chief's tenure, they should have called for a debate on the need for and legitimacy of any extension," said a joint statement by the two bodies.