The monies already paid into the IVA would be distributed to your creditors in accordance with the terms of the arrangement.
Depending upon your circumstances - ie the amount you would receive in redundancy pay, and your expectations of finding a new job, would dictate whether the IVA would eventually have to be terminated or not. Redundancy pay would be expected to be used to cover the loss of your income in the meantime, during which period your IVA contributions ought to be maintained - and your IP could ask creditors to ratify a payment break if you could anticipate finding a new job over a reasoable period, and you could then make up the lost payments at the end of the arrangement.