The groups that work in the public services, school cleaning and catering, etc., should become worker co-operatives.
I worked in hospitals when the 'hotel services' were 'in house'. I never could see why anyone thought that a private company, who had to make a profit out of providing the service, could do it any better or any more cheaply. There wasn't any apparent waste or inefficiency when it was in house.
I also worked in a school which had its catering 'privatised'. As I recall, we still had to pay the private company out of our budget, which didn't actually save us any money and the food was so poor we took it back in house anyway after a few years; I believe at a saving. I can't remember how we paid the company (annually or monthly?), but there is no reason why, if payments to Carillion cease, a school couldn't take back responsibility for their own catering, paid for by what would have gone to Carillion. (For some reason our school cleaning and maintenance was never privatised...)