Days after the mass release of hundreds of terrorists in exchange for Gilad Shalit, Palestinian Authority Chairman Mahmoud Abbas has released a surprise demand, and is calling on Israel to release 1,000 more.

Abbas claims that former Prime Minister Ehud Olmert promised him that if Israel were to free Hamas terrorists in exchange for Shalit, it would also free Fatah terrorists, in order to avoid hurting Abbas’ political standing. In an interview with TIME Magazine, Abbas said the deal was kept secret so that it would not affect negotiations for Shalit’s freedom.

Olmert promised not only to free more terrorists, but to free “more” in terms of both numbers and “quality,” a term usually used by the PA to mean terrorist leaders and those with significant time left in their sentences.

Sources close to Olmert admitted Friday that the former prime minister had indeed made a commitment to Abbas, and had planned to release roughly 550 terrorist prisoners loyal to the PA chairman.

Abbas told TIME that he plans to contact Netanyahu in the upcoming days to demand that he honor Olmert’s deal. “I’m not going to argue with him… or talk in details about it. Either, or,” he declared.

Former Prime Minister Ehud Olmert confirmed on Friday he had made such a promise to Abbas. Negotiations for Shalit’s release collapsed and restarted several times since Olmert left power in late 2008, however.  It is unclear why promises made by Olmert in previous failed negotiations would be considered binding by the Netanyahu government.

Abbas’ latest demand follows his insistence that Netanyahu freeze all construction for Jews east of the 1949 armistice line if he wants to negotiate – a demand the PA has not made in negotiations with previous prime ministers. The status of land east of the armistice line is one of the core controversial issues to be resolved in talks.