Simon:
If you have a look at, that other web site 
, I am sure that they will also point out this fact. After 4:30 waiting time, after your book-in time, you are entitled, by law, to a cooked meal, supplied by the company who have kept you waiting. IE, they pay for it.
Simon, not wishing to dispute what you are saying, but do have any authorative reference for the above. I have heard that Tesco’s will provide a meal after four hours, but I can’t find anything requiring them to do so.
I was recently at Asda, Skelmersdale, and their policy was to allow the use of their canteen after 4 hours on site.
I have found a document produced by the HSE which contains the following
W E L F A R E
Sanitary conveniences and washing facilities
Suitable and sufficient sanitary conveniences and washing
facilities should be provided at readily accessible places. They and
the rooms containing them should be kept clean and be
adequately ventilated and lit. Washing facilities should have
running hot and cold or warm water, soap and clean towels or
other means of cleaning or drying.
Drinking water
An adequate supply of wholesome drinking water, with an upward
drinking jet or suitable cups, should be provided. Water should
only be provided in refillable enclosed containers where it cannot
be obtained directly from a mains supply. The containers should
be refilled at least daily (unless they are chilled water dispensers
where the containers are returned to the supplier for refilling).
Bottled water/water dispensing systems may still be provided as a
secondary source of drinking water.
Facilities for rest and to eat meals
Suitable and sufficient, readily accessible, rest facilities should be
provided. Rest areas or rooms should be large enough, and have
sufficient seats with backrests and tables, for the number of workers
likely to use them at any time. They should include suitable facilities
to eat meals where meals are regularly eaten in the workplace and
the food would otherwise be likely to become contaminated.
Seats should be provided for workers to use during breaks. These
should be in a place where personal protective equipment need
not be worn. Work areas can be counted as rest areas and as
eating facilities, provided they are adequately clean and there is a
suitable surface on which to place food. Where provided, eating
facilities should include a facility for preparing or obtaining a hot
drink. Where hot food cannot be obtained in, or reasonably near to
the workplace, workers may need to be provided with a means for
heating their own food.
Canteens or restaurants may be used as rest facilities provided
there is no obligation to purchase food.
And a little extra note, for the ladies,
Suitable rest facilities should be provided for pregnant women and
nursing mothers. They should be near to sanitary facilities and,
where necessary, include the facility to lie down.
So if the bay is not near to sanitary facilities, ask them where you can lie down. 
Again, this is an HSE publication that they will post (single copies) to home addresses. Always useful to be armed with Government material. 
Welcome to TruckNet,Silver Surfer.
