Foreign Minister Tzipi Livni on Tuesday accused Israeli Arab MK Ahmed Tibi of trying to sabotage long-running diplomatic efforts devoted to bringing about the two-state solution.

"Tibi's problem is beyond what happened in Doha. It's highly unfortunate, in light of the fact that he served once as Yassir Arafat's adviser, and that on the eve of the Annapolis Conference he worked together with the Palestinians to undermine the conference," Livni told Haaretz shortly before leaving Qatar on Tuesday.

The foreign minister added that Tibi's standings "threaten the principle of the two-state solution."

"Tibi can continue to be a citizen with equal rights in Israel, but if a Palestinian state is founded, it will be a solution for the national aspirations of the Palestinian people.

"Whoever remains in Israel after that point can remain a member of a minority with equal rights," Livni added.

At Livni's visit to the Doha Conference on democracy, Tibi said that "Israel discriminates against Arab citizens and has established an apartheid state in the occupied territories where Arabs have different roads and different laws. How can you speak of democracy when you speak of a Jewish state?"

Liberman: Hitler was also elected democratically

Arguing that Adolf Hitler too was elected democratically, Yisrael Beiteinu head MK Avigdor Lieberman called for the dismissal of Tibi from his position as deputy Knesset speaker after Tibi told Foreign Minister Tzipi Livni, during her diplomatic visit to Qatar, that Israel is an "apartheid state."

"Any parliament that respects itself would not let this happen. Tibi is using the international forum to hurt Israel's name and status," the right-wing party leader said.

When Lieberman was told that Tibi was elected by the Knesset democratically, he answered that "Hamas were also chosen democratically and so was Hitler."

Lieberman added that "this is not about democracy. We are more like the Republic of Weimar than a democracy."