CBL and CBA

our union will be calling a general assembly in relation to our coming CBA,to be included in the proposal for the CBA is a provision on the union security clause that would include something like"any member who would not signed the CBA agreement and the special assesment authrozation(deduction of 10% of signing bonus)would automatically be removed fom being a member of the union. my question is would this violate the due process?could it be legal?is the said provision in its nature should be included instead in the union consti and by laws? another provision that the union wants to be included or submit for approval to the membership is a prohibition in forming groups,or members assembling themselves,as it may give rise to forming another union(thats what the officers reason for the prohibition)..what particular law in our labor could possibly be violated by the proposals?