What references does it make to TUPE? TUPE rights can't be removed through a current contract, i.e. you cannot say that xyz benefit will not apply in the event of TUPE (although some, such as pension contributions, are exempt from TUPE by law).
You can ask for an explanation of the changes to your contract, and you are entitled to challenge them: https://www.gov.uk/your-employment-contract-how-it-can-be-changed/dealing-with-problems
You can ask for an explanation of the changes to your contract, and you are entitled to challenge them: https://www.gov.uk/your-employment-contract-how-it-can-be-changed/dealing-with-problems