Problems with parent responsibility

I have a Consent Order drawn up and both me and ny stbx are to give notice of holidays etc, however the problem I now have is I work shift work and therefore if my stbx asks for me to have my daughter so he can go away unless I ask my Mother I have no ways of doing this. He has now asked for two plus weeks off to go away with his partner. I can not get time off and my mother will be on holiday at the same time thereore I am unable to help out. He says its my problem but I do not see this as I work unreasonable hours and do not drive so I have no way of getting childcare like I would if I worked normal hours etc. I do not know what to do because I cant just not go to work for two weeks, and there is no one else that can have my daughter. Can someone advise me?