 The Constitution was amended in 1991 to provide for an Elected President who has veto power in the use of national reserves and appointments to public office.The opposition parties have complained that the GRC system has made it difficult for them to gain a foothold in parliamentary elections in Singapore, and the plurality voting system in the constituencies of Singapore, especially large group representation constituencies, tends to exclude minority parties.The system has been defended by the PAP because the system encourages representation of the minority "races" by requiring a minority candidate in group representation constituencies.