Zero hour contracts and NMW

From today exclusivity clauses in zero hour contracts are unenforceable.  However, where a zero hour contract does contain an exclusivity clause this may be used as evidence to indicate that the worker is actually an employee.
 
We are still awaiting regulations on the anti-avoidance element.
 
Also from today the penalty of up to £20,000 for underpayment of the national minimum wage (NMW) now applies per worker, rather than per employer notice of underpayment.