An initial report from The News Teller about today's proceedings in the Supreme Court of Pakistan in the cases challenging the 18th and 21st Amendments to the Constitution indicates that the federal authorities had not filed a response to the numerous constitutional petitions:
All provincial government submitted their responses today in Supreme Court except [the] federal government.
During the hearing session, Justice Anwar Zaheer Jamali inquired from the AG about any response from the federal government. The AG replied that the federal government was served by a notice without any order to submit a response.
Justice Sheikh Azmat Saeed told the AG to read out the order of the last hearing in front of the court that is clearly demanding the response from federal government. In response, the AG asked for three days time to submit a response which the court granted.
On February 12, a three-member bench headed by Chief Justice (CJ) Nasir-ul-Mulk heard the petitions against the 21st Amendment. The federation as well as provinces had asked for time to submit responses in court. The CJ had allowed 10 days to submit responses, adjourning the case till February 24.Other news accounts, such as this one, purport to summarize a federal response. If any reader in Pakistan can clarify matters, please post a comment (real names, please).
Postscript: It says here that the judges referred the question of convening a larger bench to the Chief Justice, who was not present.