Mr Singhvi has repeatedly called the arrest by the CBI an "insurance arrest".
Welcoming the bail given to Arvind Kejriwal, Senior Advocate Abhishek Manu Singhvi has said that his client is the Delhi chief minister and no power, except the elected government or President's rule, can change that status.
Speaking exclusively to NDTV on Friday, Mr Singhvi, who is also a Rajya Sabha MP and a Congress leader, claimed that the AAP chief can also sign all files, except those pertaining to the liquor policy case under which he was arrested.
Emphasising that the relief given to Mr Kejriwal by the Supreme Court was a "well-deserved release", Mr Singhvi said that both judges on the bench - Justices Surya Kant and Ujjal Bhuyan - were unanimous on the fact that he deserved to be released on bail.
Mr Singhvi has repeatedly called the arrest by the CBI, which came after Mr Kejriwal was granted bail by a trial court in the case filed by the Enforcement Directorate, an "insurance arrest" and he reiterated on Friday that the agency should not have arrested him.
To a question on the judges disagreeing on the illegality of the arrest by the CBI, Mr Singhvi said there are several nuances to that which need to be considered and added that the issue would not go to a larger bench.
"It does not technically go to a larger bench for an interesting reason - both judges have agreed on the result, which is release. So, on a question of law, they could or could not have referred it (the matter to a larger bench) and they haven't. We'll see what happens after that," he said.
Stressing that no new conditions had been imposed on Mr Kejriwal, the senior advocate said, "It is a canard to say he can't act as chief minister. The conditions which you have mentioned have been there for several months in the ED matter, not a single new condition has been put. He is entitled to deal with, and sign, all files, except those related to this case."
"Unfairly and wrongly, the Delhi lieutenant governor's office had stopped dealing with matters unless signed by him. That part is available to him to sign with the specific clause by the Supreme Court that any file requiring the chief minister's signature to go to the lieutenant governor shall also be signed by him," he claimed.
"In Constitutional law, in practice, in real life, in public life, in law, there is nothing known as a half chief minister, a quarter chief minister. He (Mr Kejriwal) is the chief minister and no power, except the elected government or Article 356 (President's rule) can change that status," he asserted.