They'd have a job with me. I'd phone the police. Threatened to do that once in a restaurant where I was complaining about the bill... I'm quite nice really - just have a strong awareness of my rights and don't like it when people try to strongarm me
In the rest of the UK, a shop or restaurant manager or whoever would be legally allowed to force you leave if they didn't want you bf-ing on their premises. Management reserves the right and all that. So yes, technically they could forcibly evict you, call the police etc etc. Unlikely but theoretically possible under the current laws (or lack of 'em).
It terrible that still some people would ask a b/f mum to leave the premises it infuriates me at times.
Years ago my friends sister was b/f her baby in asda cafe in our centre and a woman went of on 1 staying she should goto the toilet to feed the baby, friends sisters partner was furious asking if she would eat her lunch in the toilet, she said no, he then replied dont expect my son to be fed there then