Is there a legally mandated filing fee and/or deposit?

LAW on Election of Members ofthe National Assembly (LEMNA) and Amendments of Law on Election of Members ofthe National Assembly

Art. 42 (new)

Any candidacy or list ofcandidates of a political party that is rejected by the National ElectionCommittee, that candidate or concerned political party shall have their rightto appeal in writing to the Constitutional Council within five (5) days afterthe date receiving the rejection notice.

...

The Constitutional Councilshall examine and decide on the appeal within ten (10) days after the datereceiving the appeal. In the event of dissolution of the National Assemblybefore the end of its mandate, the Constitutional Council shall immediatelyexamine and decide on the appeal.

Source:

http://www.necelect.org.kh/nec_english/index.php?option=com_content&view=article&id=93&Itemid=216