The social dimension and cohesion : complementary or contradictory?

It is again being argued that the low labour costs and social standards in countries on the periphery of the EC - Greece, Ireland, Portugal and Spain - jeopardise employment in the northern EC countries and the social safety net they have constructed. A common social policy harmonising employment and social standards to safeguard the social status quo is therefore being advocated. How valid is this argument? What consequences would the implementation of such a "social action programme" have for the economies on the periphery? How are the Community's objectives with regard to cohesion and social policy to be reconciled?