I am currently in UNITE and am voting no to a strike - if the result comes back as a yes, i shall break the strike and come to work. However, i am not sure about leaving the union 'cos i may need them one day to stand in my corner for, let's say a disciplinary?
If you break the strike while still a member of the union, don't expect them to be on your side if you need them down the line. However, for things like legal support or a disciplinary, you can be a member of any union, it doesn't have to be the recognised one for your business area. So if you're concerned about losing that side of things, you can simply join any union you wish to, and they will provide the same support.