In addition to these legal texts , there are many guidance and interpretative documents , collectively referred to in the remainder of this paper as the `` guidance publications '' , on PPPs . They include the European Commission ( EC 's ) `` Interpretative Communication on the application of Community law on Public Procurement and Concessions to Institutionalised Public-Private Partnerships '' , which seeks to address lack of legal certainty in relation to the involvement of private partners in such projects which , the EC notes , may undermine their success .