Most of the experts who participated in the preparation of the examination as part of the investigation against the fifth President of Ukraine (2014-2019), People's Deputy, leader of the European Solidarity party Petro Poroshenko in the case regarding the Kharkiv Agreements and the enshrining in the Constitution of Ukraine the intention to join the EU and NATO, have resigned from the Center soon after completing work on this case, the Bukvy publication wrote on Thursday.