He was due to he sentenced in court last month, before it was again adjourned until today.
Siddiqui, through lawyer Tom Sutcliffe, withdrew his guilty pleas.
Sutcliffe told Judge Glen Marshall he will withdraw as his lawyer - one of many Siddiqui has now used - and a new application for legal aid will need to be filed.
Judge Marshall told Siddiqui the matter has been in the system for "a considerable amount of time" causing inconvenience to potential victims and other court users and it needed to be resolved.
He set the matter down for timetabling to allow him to keep a close eye on developments.
Siddiqui was remanded in custody and will reappear via audio visual link later this month.