Thanks for the advise, we will begin to keep a log of this from today. I have her contract in front of me the relevent section:
ADDITIONAL HOURS:
Reasonable effort will be made to give you advance notice, should you be required to work additional hours. These hours will be at your normal rate of pay until such time as your weekly hours exceed 40. Thereafter you will be eligible for either time off in lieu or payment at your normal rate.
and from the handbook:
ADDITIONAL HOURS:
If you work more than your contracted hours you will be entitled to:
<40 hrs = pay @ basic or TOIL
>40hrs = TOIL
Note: it is part of normal management responsibilities for managers to work some additional hours . No extra payment will be made for additional time worked, however in exceptional circumstances, time of in lieu may be approved. Continually working excessive hours is not encouraged.
Update: the girls had their "counselling forms" today (one down from disciplinary) for:
1. breach of company security procedures (walking out back door setting off alarm)
2. failing to carry out reasonable instruction from your line manager.
3. leaving shopfloor at end of night before manager has inspected it.
disgraceful really and there is no time logged for these incidents on the form (when work hours were over!). One of the girls phoned head office HR to see about the 20 minute rule and was told employees must not be kept no longer than 5 minutes unpaid, and all overtime should be paid. My girlfriend has worked there for 2 years @ NMW 5.52.
I told her not to sign the counseling form but the silly cow has

under pressure from management. One of the girls has raised a grievance in the counselling interview but was told again she can be kept for up to 20 minutes (which disagrees with HR phonecall).
Should they just walk out again at 7.10pm or keep raising this further. Last year I was on the verge of calling the cops after sitting outside waiting for her until 7:30pm as they are locked in. Would be a great one for the papers.