Who administers direct democracy mechanisms at the national level?

The National Elections Act from 2008 (Act no. XI of 2008)http://www.cmi.no/sudan/doc/?id=1035

Chapter Nine

Referendum

Reference to Referendum Art. 85. In accordance with the provisions of Article 217 of the Constitution, the Commission shall refer to the people for referendum any matter of national or public interest which is referred to it by the President of the Republic or the National Assembly by resolution passed by more than half of its members.

The Interim National Constitution of the Republic of Sudan (from 2005) http://www.mpil.de/shared/data/pdf/inc_official_electronic_version.pdf

Art. 141 (2) The National Elections Commission shall be the only bodyto assume the following functions:-(c) organize and supervise any referendum inaccordance with this Constitution without prejudice toArticles 183 (3) and 220 (2) herein,