a) There is collective bargaining agreement

b) Genuine unions are to weak to force one

c) The employer or a employers association seeks themselves a union and negotiate a agreement

d) In the individual agreements with employees a new clause incorporating the collective agreement is inserted

(It is probably a high fluctuations sector anyway or you can use move the employees to sign new treaties - no union they can complain too)

e) The individual agreement makes the collective agreement legally binding (It would be binding for union members of the contracting union anyway, but we assume few exists)

I can't use "contract"?