1) A collective agreement concluded in a bargaining council may alter, replace or exclude any basic condition of employment if the collective agreement is consistent with the purpose of this Act and the collective agreement does not--
a) reduce the protection afforded to employees by sections 7, 9 and any regulation made in terms of section 13;
b) reduce the protection afforded to employees who perform night work in terms of section 17(3) and (4);
c) reduce an employee's annual leave in terms of section 20 to less than two weeks;
d) reduce an employee's entitlement to maternity leave in terms of section 25;
e) reduce an employee's entitlement to sick leave in terms of sections 22, 23 and 24;
f) conflict with the provisions of Chapter Six.
2) A collective agreement, other than an agreement contemplated in subsection (1), may replace or exclude a basic condition of employment, to the extent permitted by this Act or a sectoral determination.
3) An employer and an employee may agree to replace or exclude a basic condition of employment to the extent permitted by this Act or a sectoral determination.
4) No provision in this Act or a sectoral determination may be interpreted as permitting--
a) a contract of employment or agreement between an employer and an employee contrary to the provisions of a collective agreement;
b) a collective agreement contrary to the provisions of a collective agreement concluded in a bargaining council.