Lawmakers may have to sign non-disclosure agreements before meetings in which they are exposed to confidential information, Knesset House Committee chairman Yoav Kisch proposed Monday.Kisch called the meeting after a confidential report by former Foreign Affairs and Defense Committee chairman Tzachi Hanegbi (Likud) on 2014’s Operation Protective Edge leaked to the press, but said there are other confidential committees and subcommittees in the Knesset, and the meeting addressed how to prevent the general phenomenon of leaking.According to Kisch, the leak not only directly damages Israel’s security as a result of the information revealed, it hurts the committee’s ability to function, because officials are reluctant to give it classified information.“I will fight the leaks. It cannot be that there is no way to prevent MKs from leaking confidential materials,” he said. “The Foreign Affairs and Defense Committee is the most discreet in the Knesset, and we must keep it that way.”The House Committee chairman called for MKs to take polygraph tests to see who leaked the document, facing opposition from Knesset Legal Adviser Eyal Yinon and Foreign Affairs and Defense Committee chairman Avi Dichter.Yinon said polygraph tests for elected officials have both constitutional and practical problems.On a practical level, Yinon explained, polygraph tests do not give totally accurate results, which is why they cannot be used as evidence in criminal cases. Constitutionally, he added: “Such tests, administered by the executive branch, undermine separation of powers and limit the legislature’s ability to examine [the executive branch].”Yinon saw less of a problem with having MKs sign a non-disclosure agreement as a deterrent, though he said that leaks do not happen very often, so special rules beyond the criminal code do not have to be created to deal with them.The legal adviser pointed out that “leaking confidential materials is a crime, and the attorney-general can order an investigation, which can lead to the end of an MK’s tenure if he is found guilty with moral turpitude.”Yinon also pointed to the legal precedent of then-opposition leader Benjamin Netanyahu revealing contents of a classified document about government negotiations to give the Golan Heights to Syria in 1995. The High Court said he was not guilty of a crime, because the act was unplanned and a response to then-foreign minister Shimon Peres accusing him of lying about the negotiations.Dichter also called on MKs to stop talking about polygraphs, saying it is an unreliable method.“If there’s a leak of confidential information, we can ask for an investigation, and the investigators will decide what tools to use. Often, polygraphs are not one of them,” he stated.Dichter said that leaks should not be ignored, but a serious response like a criminal investigation should not be taken lightly, and only be used when the leak is damaging enough to warrant it.“I think that deterrence mostly worked until now,” he added. MK Yifat Shasha-Biton (Kulanu) expressed dismay at the lack of punishments for leaking.“We all have a great responsibility on our shoulders,” she said. “It sounds absurd to make us sign a non-disclosure document, because who doesn’t know now that we can’t reveal the information, but it must be done if there are leaks, even if they are rare.”MK Amir Ohana (Likud) said he would be willing to sign a document and take a polygraph test, and “anyone who refuses must have something to hide.”At the end of the meeting, Kisch asked Knesset Security Officer Yosef Griff, who is responsible for data security, to research how foreign parliaments deal with this issue in order to prepare new instructions.Also Monday, the Foreign Affairs and Defense Committee bade farewell to Hanegbi, as he became a minister without portfolio last week.During the meeting, Hanegbi apologized to Yesh Atid MK Ofer Shelah, whom he accused of leaking the Protective Edge report.