Israeli Attorney-General Yehuda Weinstein said on Sunday that a planned Knesset parliament vote to set up a probe of funding sources of left-wing NGO's could violate basic human rights.

The Knesset is set to vote next week whether or not to establish two inquiries panels to run such an investigation.

"It is impossible to ignore the chilling effect of such investigative panels, should they be established, on fundamental rights such as freedom of expression, freedom of conscience, and freedom of association," Weinstein wrote in the state's response to a petition opposing such panels, the Ha'aretz daily reported on Monday.

If the vote passes, the panels would be tasked with looking into the funding sources of groups that "carry out the delegitimization of the Israeli Defense Forces," and purchases of land by suspected Arab organizations abroad.

Parliamentarians opposed to the planned probe said "For the first time, the proposed panels address clearly ideological issues and seek to deal with entities identified only with one side of the political map, which are currently in the opposition."

A slight majority of 61 out of 120 Knesset members are for the plan, with 59 opposing the idea, according to a survey by the newspaper.

The issue came to fore several weeks ago when a 10 to 7 vote was passed to set up such an investigation.