A sleeping giant is about to be woken and its causing panic. If there is imposition then permission will not be an issue. I cant see Unite turning down its biggest customer and in fact the biggest trade union branch in Europe!!!
Not entirely sure it's causing panic. I can't say I've spotted too many signs of that at work to be honest.
Like I wrote earlier, the BASSA members, the BASSA reps, Unite and Tony Woodley had better be extremely sure that a) any strike is 100% legal on any and every level and b) the support of the membership is definitely there. Otherwise, it's likely to be the most ineffectual and self-defeating industrial action in the UK in recent years.