The UN's judicial body heard India's observations in the first phase of the proceedings, which are being conducted at the Peace Palace in The Hague.
As the proceedings began, India appealed to the UN's top court to order Pakistan to suspend its planned execution of Jadhav , saying his rights had been violated by Islamabad.
Senior advocate Harish Salve, leading the Indian legal team, focused his arguments on Pakistan's denial of consular access to Jadhav as he presented India's position before the judicial body, international media reported.
“The situation in which we find ourselves is grave and it is urgent,” Salve said. “India has made innumerable requests since March 2016 for consular access.”
The hearing focused on India's request for so-called “provisional measures” that can be granted at short notice to ensure a dispute between states does not deteriorate during full ICJ proceedings, which typically take several years.
Jadhav was “an innocent Indian national, who, incarcerated in Pakistan for more than a year on concocted charges, deprived of his rights and protection accorded under the Vienna Convention, has been held incommunicado... and faces imminent execution,” Mittal told the tribunal.
Pakistan has failed to respond to all Indian demands for information about the case, snubbing requests for documents including the charge sheet, and has failed to provide Jadhav with consular access, Mittal said.