"Exile is not an option. Return is definite but the matter will take some time and arrangements. I want to set the rules of the game," Bishara told Al Jazeera.
"I have commitments now with other countries which I cannot make if I were there. This is why I decided to end my responsibilities with my former post," he added.
He said that if he stayed in Israel the legal proceedings against him could drag on for years.
"There's no point now to clinging to parliamentary status and immunity in this right-wing, fascist, racist orchestra," he added.
An Israeli court last week partially lifted a gag order on the inquiry into Bishara, allowing police to announce that its international crimes unit is investigating him.
The 50-year-old entered the Israeli parliament in 1996 and three years later became the first Arab Israeli to run for prime minister.
He later joined the National Democratic Assembly, or Balad, which was formed following the Oslo accords between Israel and the Palestinians.
Bishara has previously made solidarity visits to countries such as Syria and Lebanon, which Israel designates as its enemies.