The following information was received from: 
Pejman Akbarzadeh
Member of ARTISTS WITHOUT FRONTIERS (Tehran Chapter)
Minor edits done by Hannah Grap, Language Weaver

FARSI  (which is originally PARSI) is the native name of the language and PERSIAN is its English equivalent; as the native name of German language is 'Deutsch', but we never use 'Deutsch' in place of 'German' in English; or the native term of the Greek Language "Ellinika" for "Greek," or "Espanol" for "Spanish".

The titles of dictionaries that have been written by several great Persian scholars (e.g. Prof. Moein, Prof. Aryanpour, Prof. Baateni, etc.) are "English-Persian Dictionary" not "English-Farsi Dictionary":
http://www.mazdapublishers.com/Farhang-EP.htm
http://www.aryanpour.com/

The official institution "Farhangestan; The Academy of Persian Language and Literature, in Tehran" ( www.PersianAcademy.ir)  in an announcement has rejected the use of the word 'Farsi' instead of 'Persian' in English.

According to Dr. Hossein Sameie (visiting linguistics professor of Emory University in Atlanta), "PERSIAN, alongside the name of a language, may be used, as an adjective, for the other aspects of our history and culture. For example, we can speak about 'Persian Literature', 'Persian Gulf', 'Persian Carpet', 'Persian Food'; this way, 'Persian' may be a common concept and function as a link between all aspects of Iranian [Persian] life, including language. 'Farsi' does not have such a characteristic."

And finally, all international broadcasting centers (e.g., BBC, VOA, DW, etc.) have "Persian Service" not "Farsi Service"

BBC : www.bbc.co.uk/persian/index.shtml
VOA : www.voanews.com/persian/index.cfm
DW : www.dwelle.de/persian/
Radio Free Europe : www.rferl.org/bd/ir/  
Radio France Internationale: www.rfi.fr/fichiers/Langues/rfi_persan_main.asp

The same is true for the following:

"Persian Linguistics Association”:
www.persiandirect.com

"American Association of Teachers of Persian" (AATP):
http://homepages.nyu.edu/%7Emmk4/AATP.htm

"The Centre for Promotion of Persian Language and Literature":
http://www.apersian.org/

Oxford University:
http://www.orinst.ox.ac.uk/nme/persian_info.shtml

Columbia University:
http://www.columbia.edu/cu/mealac/languages/persian/

Yale University:
http://students.yale.edu/oci/ycps/ycpsProgramCourses.jsp?subject=PERS&dept=Persian
etc.

In English, usage of "Farsi" in place of "Persian,"  is as inaccurate as using "Farsi Gulf" instead of "Persian Gulf."