Israel Beiteinu on Tuesday rejected a claim in former US ambassador Martin Indyk's new book that party leader Avigdor Lieberman had conducted a secret dialogue with Palestinian negotiators at the end of former US president Bill Clinton's administration. "It's so much of a stretch, it's really hearsay over hearsay," Israel Beiteinu Knesset list member and former Israeli ambassador to the US Danny Ayalon told The Jerusalem Post on Tuesday. "It really doesn't sound credible. Not to mention, we're talking about something that happened about 10 years ago. I mean, Lieberman was a private man in those days. He wasn't even involved in politics." In his book, Indyk recounts that the Palestinian negotiator who met with Lieberman, Muhammad Rachid, reported that he had secured the right-wing leader's support for then-prime minister Ehud Barak's plan for territorial compromise, as well as current Prime Minister Ehud Olmert's agreement to give up Israeli sovereignty over the Temple Mount. As reported by the Post on Tuesday, Indyk did not indicate whether he believed Rachid's claims, nor did he include a response from Lieberman or Olmert. However, the former ambassador did say that Palestinian leader Yasser Arafat's reliance on the information had been part of what led him to believe he didn't need to make a deal with Barak at Camp David, since the Israeli Right would also make the same concessions. In addition to Ayalon's response, the party's spokesman issued a statement that said simply, "The facts as they are portrayed in Martin Indyk's book are untrue." The party - which received 19 mandates for the upcoming elections in a Likud poll released Tuesday - also responded to a story that Lieberman had been a member of the outlawed Kach organization in the 1980s, calling it a "deliberate provocation" and denying it out of hand. "We deny every detail of this story and view it as a deliberate provocation," a statement from the party read. "The success of Israel Beiteinu has been generated despite a level of lies and baseless slander against us on levels that the political and media systems have never known." The report, published in the Haaretz newspaper on Tuesday, revealed that former Kach secretary Yossi Dayan said he had been the one to issue Lieberman his Kach membership card while the Knesset member was still a new immigrant. However, he was unsure of the degree of Lieberman's involvement with the party. "I don't recall to what extent he was active in the movement," Dayan reportedly said. "But if he denies [this], I am ready to testify in any forum that Lieberman was indeed a member for a short amount of time." The Labor Party also responded to the story, calling upon Central Elections Committee head Judge Eliezer Rivlin to speedily examine the report. "The story confirms what we have already known about the ideas of both Lieberman and [Rabbi Meir] Kahane, whose movement, Kach, was outlawed," the Labor statement said. "Lieberman is a fascist, a racist who endangers the internal and external security of Israel, and in fact, the existence of democracy in Israel."