The petitioners had argued that the criminal defamation under these sections of the IPC travelled beyond constitution's article 19(2) that imposes reasonable restriction on the freedom of speech and expression.
The verdict was reserved on August 13 last year after bench of Justice Dipak Misra and Justice Prafulla C Pant heard the matter spread over a month.
Swamy and Gandhi have been charged with criminal defamation under Sections 499 and 500 of the IPC for their political speeches made in Tamil Nadu and Maharashtra respectively, while Kejriwal is facing cases under the same provisions lodged Union Minister for Road Transport and Highways Nitin Gadkari and others.