1) Yes. Economic operators are free to organise themselves as they so wish, i.e. they can submit a tender as a single tenderer, or participate in a joint tender, or be a subcontractor. No limitation can be set as regards joint tendering and subcontracting. In principle, the direct participation (consortium) or indirect participation (subcontracting) of one and the same economic operator in more than one tender for the same procurement procedure is acceptable. 2) Yes. However, the contracting authority reserves the right to examine the tenders in case it suspects distortion of fair competition (like in the case of a number of tenders with the same legal entity participating in all of them) and exclude the tenderers concerned in case it is proved.