Dick Dasterdly
Read my previous posts on this subject which will answer your questions.
The employer has to give the employee 3 months notice to change your T & C's.
Then you either agree to the change or put it in dispute.
Regarding should you bail out only you can answer that,you may be entitled to redundancy(only if you have employed for over two years) if there is not job for after the takeover.
Something else you may want consider is if you bail out is any better than staying where you are, my experience is all handling agents are all very much the same.
Give your fulltime Union officer a ring and they will advise you.