Contracting authorities may at any moment during the procedure exclude an economic operator where it turns out that the economic operator in question is, in view of acts committed either before or during procedure, in one of the situations referred to in Article 55(1) to (3).
This is a relevant clarification that prevents a rigid interpretation that would have limited the possibility to exclude tenderers at the beginning of the procurement process (ie only at selection stage).
Notwithstanding the above, and maybe most interestingly, this provision is coupled with a new Article 55(3)(d) in virtue of which a tenderer can be excluded
where the contracting authority can demonstrate that the economic operator has entered into agreements with other economic operators aimed at distorting competition.
This is an important development in terms of reducing the impact of bid rigging on procurement, which stresses the need for contracting authorities to cooperate closely with competition watchdogs (both at regional and national levels, and with the European Commission's Directorate General for Competition) and that opens the door to potential difficulties in terms of due process (eg what is the burden of proof to be discharged by contracting authorities?) and an eventual conflict of enforcement competences (both by administrative bodies and in terms of judicial review, particularly where competition matters are assigned to specialised courts).
Therefore, when the time to transpose Articles 54 and 55 of the new Directive (if adopted in the terms of the compromise text) comes, it will be interesting to revisit the institutional architecture of procurement authorities to ensure the appropriate collaboration channels with antitrust authorities (on this, see A Sanchez Graells, Public Procurement and the EU Competition Rules  Hart Publishing 381-389).