Tirkel has said he would summon Binyamin Netanyahu, the prime minister, Ehud Barak, the defence minister, and Lieutenant-General Gabi Ashkenazi, Israel's military chief, to appear.
Netanyahu has said he, Barak and Ashkenazi would testify.
Other military personnel are not likely to appear before the panel but will be questioned in a separate military investigation.
Amid an international outcry over the raid, Israel rejected a proposal by UN Secretary-General Ban Ki-moon for an international inquiry, but appointed two foreign observers - David Trimble, a Northern Ireland politician and Nobel Peace Prize laureate, and Canadian jurist Ken Watkin - to the panel.
Tirkel has said the commission's mandate calls for an examination of whether Israel's naval blockade of the Hamas-controlled Gaza Strip and the flotilla's interception conformed with international law.
It also will investigate the actions of the convoy's organisers and participants.
Israel has said its commandos were enforcing a blockade necessary to prevent weapons from reaching Hamas fighters in the Gaza Strip and that they only opened fire when activists with knives and clubs assaulted a boarding party.
In response to Western criticism, including from its biggest ally, the United States, Israel has since eased the land blockade of Gaza, allowing most civilian goods through, while continuing to enforce the naval embargo of the coastal territory.