(1) An employer shall not make a deduction from the wages of an employee (or receive any payment from an employee) unless -

(a) the deduction (or payment) is required or authorised to be made by virtue of any statute or any instrument made under statute,

(b) the deduction (or payment) is required or authorised to be made by virtue of a term of the employee's contract of employment included in the contract before, and in force at the time of, the deduction or payment, or

(c) in the case of a deduction, the employee has given his prior consent in writing to it.

(2) An employer shall not make a deduction from the wages of an employee in respect of -

(a) any act or omission of the employee, or

(b) any goods or services supplied to or provided for the employee by the employer the supply or provision of which is necessary to the employment,

unless -