If you are entitled in law to a redundancy payment (i.e. you have worked for your employer for 2 years or more and are being made redundant), you cannot be made to give up or 'sign away' that right, no matter what your contract says.
Fixed-term workers who have been employed under a contract for two or more years (by virtue of the Fixed-term Worker (Prevention of Less Favourable Treatment) Regulations 2002) cannot be made to give up their right to a redundancy payment.
