Is it possible to change the terms of a contract by dismissing an employee then re-engaging him or her under different terms?

If the employer has a genuine business need to change the terms of the contract and dismisses and re-engages in order to do so, it has been held that the dismissal will be for "some other substantial reason". Depending on the numbers to be dismissed the employer must comply with the collective redundancy consultation procedure prior to notifying employees of their dismissal, or risk the payment of a protective award.