It is not clear if this is an additional requirement (in addition to fulfilling paragraph (2) on the order of quotients and votes for independent candidates) or if these two are sufficient requirements on their own. If 87 (3) is a sufficient requirement on its own, then it is mathematically redundant, since the number of votes equal to or more than three percent of the total valid votes cast will always be within the ranked quotients mentioned in Article 87 (2). However, if this is an additional requirement to be allowed to participate in the allocation of seats, then one would expect that there should be a provision to exclude independent candidates who failed to pass the required threshold from such allocation along the lines of the procedure foreseen for parties, socio-political organizations and electoral blocs in Art. 86 (3). This needs to be clarified. If Article 87 (3) is meant to be an additional requirement, then it would be more clear if it was moved up to Article 86 (2) on thresholds and independent candidates were mentioned in 86(3).
