Could I ask, how much are you paying per week for your livery, and what does that include / what area / how big is the farm / are other farming practices carried out / how many horses there?
Realistically, those small pens behind the stables in the photo are pretty useless - they won't walk around any more than if stabled, the concrete doesn't give them the opportunity to carry out any horsey behaviours, and they can't even lie down or roll there. The bedding would get dragged around, and wet in bad weather, and the door in the rear wall wouldn't allow for a bed that could be banked up in / allow space for the horse to lie down.
So, if Defra, the BHS and FEI decide that they're going to legislate that all livery yards have to provide penned hardstanding behind each stable, a tracked system and hay soaking facilities, most yards would have to close down. Where I am, the position of the stables wouldn't allow for it (hedge behind, then a stream), the cost of knocking down and re-building elsewhere would be huge, and the loss of habitat taken by concreting over an area behind the new stables would be contrary to the current DEFRA rules. Planning permission would be costly, and almost certainly refused - the majority of local councils don't rate the equestrian world as something to value. If you've tried to get road warning signs up near bridleways, you'd know that!
Currently, in my opinion, the councils are trying to reduce land used for horses (and agriculture) to get it freed up for building houses - this is how they make their money, and they don't care that once developed, that land can never come back. Many livery yards rely on farms with diversification, once a farm has change of use from farming to solely equestrian, they lose all support from DEFRA, but to remain 'agricultural', they can't lose fields to unproductive (in the sense of food production etc) areas.
Really, as a horse owner, it is your responsibility to maintain your horse's weight - and the majority of the time this is done more by giving plenty of exercise, not over rugging and over feeding than by never letting them see a blade of grass. We've had many natives, none have been on restricted grazing, at most they're just managed by going onto the field following sheep / other horses so they can't gorge, but have been exercised at least 5 days a week, for a good amount of time, at a suitable intensity. Buying low nutritional value meadow hay, avoiding feeds which are high in starch and sugar etc an getting them to actually work for their feed.