Shift Pattern Changes

[ipfreely07]

Although I am aware that an employer can change a Working Pattern with two weeks notice (Stated in my contract).

My current shift pattern, I have been on for 8 yrs now. It is a 5 Shift rotating pattern (5 teams) and the company have now changed this to 4. The 5th team (me) has been pigeon holed in to being a 'Cover' shift for holiday cover. This was done without consultation (will be chatting with them this week) and I also have to balance Nursery Childcare for my daughter along with my Wife's shift pattern (different company).
I have come up with a new shift pattern for myself that gives the contracted hours and flexibility to have minor changes when needed to cover, but have a bad feeling that my company will play 'silly buggers' later on as I will state that I require reasonable notice for childcare.

I am trying to preempt any issues they may try on with me. I have a feeling that they could try to put me on different 'patterns' with only two weeks notice.

My Question is, how many times/often can they do this?
And if so, is there anything I can do about it?