To quote the attached joint letter from the South Downs National Park Authority and West Sussex County Council,

"The draft plan has been published prior to its submission to the Secretary of State to allow representations to be made on its ‘soundness’ and ‘legal compliance’.  
Representations can be made up until 5pm on Monday 13 March 2017.
Following this period, the Plan and supporting evidence base, and the representations received will be considered by a Government-appointed Planning Inspector, at an examination-in-public to be held in summer 2017.  Once adopted, the Joint Minerals Local Plan will provide the basis for making consistent land-use planning decisions about planning applications for minerals development."

Letter

Statement of Representation Procedures