Joint eurobonds or stability bonds must go hand in hand with substantially reinforced fiscal surveillance and policy coordination, European Union Economic and Monetary Affairs Commissioner Olli Rehn said on Tuesday. "Stability Bonds would require that any step in the further sharing of risk would have to be balanced by provisions that ensure sustainable public finances and avoid free-riding on the consolidation efforts of others," Rehn said in a speech delivered in Berlin. "This would have implications for fiscal sovereignty, which calls for a substantive debate in member states." The European Commission is set to present on Wednesday proposals for economic reforms and policy coordination. The executive arm of the EU will also present a green paper on the rationale, preconditions and possible options of financing public debt through eurobonds. Taking note of the opposition to eurobonds, Rehn said they could alleviate the sovereign debt crisis. A profound reform of economic governance towards deeper policy integration is a necessary precondition for any serious move towards introducing stability bonds, he added. The official noted that tomorrow's proposals constitute an interlinked package that builds on the recent reform of economic governance and stability mechanisms and will also outline a roadmap towards the next stage of an ever closer and sturdier economic union, in both dimensions. Rehn said the debt redemption fund proposed by the German Council of Economic Experts, also known as the Wise Men, "is worth exploring seriously and further".