Defense Minister Ehud Barak went behind the government's back to try to forge a cease-fire during last year's war in Gaza, former prime minister Ehud Olmert's new autobiography claims, according to people who have seen a draft.

The book is still being written with editing help from journalist Yair Lapid, and publisher Yedioth Ahronoth has yet to set a publication date.

"What Barak did was inconceivable," one person who saw the draft told Haaretz. "He held talks with other countries' foreign ministers about a cease-fire, without the knowledge of Olmert or the cabinet."

Excerpts of two completed chapters were published in the daily Yedioth Ahronoth on Friday, and media reports since then have focused on Olmert's criticisms of Barak's conduct regarding a different military operation.

"But the truth is that Olmert wasn't referring to a single operation or isolated conduct," the source said. "Barak was a serial offender. That's the way he acted time after time, and the book reflects this."

But overall, the work will focus less on politics than on diplomatic issues, said people who have seen the book. Olmert will focus on the peace process, his ties with foreign leaders and efforts to recover three soldiers kidnapped during his term.

Olmert's comments in the excerpts published this weekend - which the former premier reiterated at an event organized by the Geneva Initiative on Monday - continued to make waves in the political world on Monday.

Weizman Shiri, secretary general of Barak's Labor Party and thus far the most senior politician to come to Barak's defense, accused Olmert of endangering national security through his remarks that related to Barak's handling of a specific classified military operation.

"I've gotten calls from people who know Olmert and say he's gone off the rails. He's talking about the most top-secret meetings, and it seems to me that Anat Kamm is now under house arrest for much less than this," Shiri said, referring to a soldier on trial for passing classified army documents to a Haaretz journalist.

"How can a former prime minister endanger Israel's security?" Shiri demanded. "Everything is personal. I prefer a hesitant, deliberative and measured minister, as he describes [Barak], to a man who shoots from the hip like Olmert."

But Shiri also insisted that from his knowledge of Barak, the minister is "100 percent different from the image Olmert tried to paint. And anyway, which Olmert are we supposed to believe - the one who's now lashing out at Barak, or the one who lauded his excellent cooperation with Barak during Cast Lead [last year's war in Gaza]?"

Finally, he accused Olmert of deliberately publishing the chapters now because Barak is on an official visit to the United States and cannot respond effectively.

Maj. Gen. (res. ) Uzi Dayan, a former chairman of the National Security Council now with the Likud party, also attacked Olmert as "serially irresponsible. He's using hints about events he knows of due to his [former] position to promote his book."

And the Ometz organization, which seeks to promote good government, filed complaints against Olmert yesterday to both the attorney general and the police, accusing him of revealing state secrets about a military operation that occurred while he was prime minister - including the fact that Barak opposed the operation. Among other legal problems, Olmert thereby violated the military censorship laws, Ometz charged.

But Olmert's spokesman, Yaakov Galanti, insisted that Olmert had done no such thing. "The military censor confirmed that Olmert was not even close to committing a censorship violation," Galanti told Army Radio yesterday.

And in another twist to the affair, it turns out that Barak might have the power to bar publication of certain sections of the autobiography - and thereby excise some of Olmert's most scathing criticisms of himself.

Barak is one of three ministers who sits on the committee that vets books by former public officials. Justice Minister Yaakov Neeman chairs the panel; the third member is Foreign Minister Avigdor Lieberman.

The panel's decisions have the same binding power as a cabinet ruling, and it has a broad mandate: It need not adduce security grounds to bar publication of certain material. By law, a civil servant cannot publish anything he learned on the job without the committee's approval, as well as that of the military censor.

Thus Barak, as one of the panel's three members, would have various means of impeding the book's publication. For instance, as one person familiar with the panel's work noted yesterday, "this is not a committee that meets regularly; it meets ad hoc, based on the books and publications submitted to it."

But thus far, the committee has not been asked to review the book, since Olmert is still writing it.