One downside of the Parallel system's increased menu of options is that two classes of MPs can be created:

• one group with districts to look after who are beholden to their local electorate, and
• a second group chosen from the party lists, without formal constituency ties, who are primarily beholden to their party leaders.

Furthermore, the fact that Parallel systems fail to guarantee overall proportionality means than some parties may still be shut out of representation despite winning substantial numbers of votes. Parallel systems are also relatively complex, and can leave voters confused as to the nature and operation of the electoral system.