Yuval Diskin, head of the Shabak Israel Security Agency, said Monday that a prisoner exchange for the release of abducted Israeli soldier Gilad Shalit would be a tremendous achievement for Hamas and a slap in the face for Palestinian Authority Chairman Mahmoud Abbas.

In a security briefing to heads of Israeli diplomatic missions around the world, Diskin said a Shalit deal would not lead to Abbas stepping down and that Abu Mazen was already preparing for the day after such a deal.