Updated

The head of Egypt's key association of judges says 90 percent of its members have voted not to oversee Saturday's nationwide referendum on the country's contentious draft constitution.

Ahmed el-Zind, the chairman of the Judges' Club, announced the decision on Tuesday.

The move is unlikely to stop the referendum from taking place, but it casts further doubt on the legitimacy of the constitutional drafting process.

President Mohammed Morsi's deputy has said that if there are not enough judges to oversee the referendum, the vote can be staggered over several days. A faction of judges loyal to Morsi has said it would not boycott the vote.

Egypt is sharply divided and polarized over the draft constitution, which was hurriedly approved by an Islamist-dominated constituent assembly despite an opposition boycott.