Who administers direct democracy mechanisms at the national level?

Law on Nationwide Referendum adopted on 14 March 2003

Art. 10

http://?pkw.?gov.?pl/?g2/?i/?00/?8.?pdf (in English - but not updated)

http://?isap.?sejm.?gov.?pl/?DetailsServlet?id=WDU20030570507 (in Polish ? the Parliament?s website)