56.—(1) Contracts shall be awarded on the basis of criteria laid down in accordance with regulations 67 to 69, provided that the contracting authority has verified in accordance with regulations 59 to 61 that all of the following conditions are fulfilled:—
(a)the tender complies with the requirements, conditions and criteria set out in the contract notice or the invitation to confirm interest and in the procurement documents, taking into account, where applicable, regulation 45;
(b)the tender comes from a tenderer that—
(i)is not excluded in accordance with regulation 57, and
(ii)meets—
(aa)the selection criteria, and
(bb)where applicable, the non-discriminatory rules and criteria referred to in regulation 65.
(2) Contracting authorities may decide not to award a contract to the tenderer submitting the most economically advantageous tender where they have established that the tender does not comply with applicable obligations in the fields of environmental, social and labour law established by EU law, national law, collective agreements or by the international environmental, social and labour law provisions listed in Annex X to the Public Contracts Directive as amended from time to time.
(3) In open procedures—
(a)contracting authorities may decide to examine tenders before verifying the absence of grounds for exclusion and the fulfilment of the selection criteria in accordance with regulations 57 to 64; and
(b)where contracting authorities make use of that possibility, they shall ensure that the verification of absence of grounds for exclusion and of fulfilment of the selection criteria is carried out in an impartial and transparent manner so that no contract is awarded to a tenderer that—
(i)should have been excluded under regulation 57, or
(ii)does not meet the selection criteria set out by the contracting authority.
(4) Where information or documentation to be submitted by economic operators is or appears to be incomplete or erroneous, or where specific documents are missing, contracting authorities may request the economic operators concerned to submit, supplement, clarify or complete the relevant information or documentation within an appropriate time limit, provided that such requests are made in full compliance with the principles of equal treatment and transparency.