"I hereby give permission for Discount Tobacco Concessions Ltd, to deduct the amount of£3,500 at the rate of£20.00 per week, for the 175 weeks.
"An employer shall not make any deduction from any wages of any worker employed by him unless the deduction satisfies one the following conditions, namely - (a)it is required or authorised to be made by virtue of any statutory provision or any relevant provision of the worker's contract; or (b)the worker has previously signified in writing his agreement or consent to the making of it."
"In this section `relevant provision,' in relation to a worker's contract, means any provision of the contract comprised - (a)in one or more written terms of the contract of which the employer has given the worker a copy on any occasion prior to the employer making the deduction in question, or (where subsection (1)(a) applies for the purposes of subsection (2)) prior to his receiving the payment in question, or (b)in one or more terms of the contract (whether express or implied and, if express, whether oral or in writing) whose existence and effect, or (as the case may be) combined effect, in relation to the worker the employer has notified to the worker in writing on any such occasion."
"For the purposes of this section - (a)any relevant provision of a worker's contract having effect by virtue of any variation of the contract, or (b)any agreement or consent signified by a worker as mentioned in subsection (1)(b),"
"shall not operate to authorise the making of any deduction, or the receipt of any payment, on account of any conduct of the worker, or any other event occurring, before the variation took effect or (as the case may be) the agreement or consent was signified."
"It is clear - indeed not argued to the contrary - that by section 1(3)(b) a variation of the original contract of employment may be oral, but that any such variation must be notified to the employee in writing prior to the date of the deduction. That is not the end of the matter because by section 1(4) the variation must have been agreed before the conduct or event on account of which the deduction is made. Thus to apply those principles to the present case the variation must have been agreed before 9 August and the notification in writing of the variation must have been given to the employee by the employers before8 December 1988 ."
"(b)any agreement or consent signified by a worker as mentioned in subsection (1)(b)"