The rules on awarding public contracts have provisions which allow the specification of social criteria, such as the requirement for employment of long term unemployed, as a condition in the performance of the contract. Any such provision must be compatible with EU law, i.e. they must be made known to all interested parties and must not restrict participation by contractors from other Member States. Subject to this, contracting authorities have the discretion to apply such conditions, as appropriate.
I understand that the National Procurement Service is currently looking at developing guidance for contracting authorities in relation to the use of such social clauses.