A real can of worms this one!.......If OT is there many will work it for obvious reasons
The crux of the current situation is that all the working hours regulations are nothing more than recommendations with most choosing to ignore via the opt out clause. Unfortunately, it's a fact that many MRO's and Airlines could not operate without Engineers working OT. If the rules below were rigidly enforced there would be a lot of trouble! (which clearly shouldn't be the case!)
According to ‘The Working Time Regulations 1998’ and ‘The Working Time (Amendment) Regulations 2003’5, an employer should ensure that a worker does not work in excess of an average of 48 hours per week over a 17-week period. In the 1998 regulations the air industry was excluded from this rule, but in 2003 this air industry exclusion was removed. However, the 48‑hour limit does not apply if a worker has agreed with his employer, in writing, that it should not apply in his case. 97% of engineers at the AMO, including Sup A, had signed an ‘opt-out’ agreement so that the 48-hour limit would not apply to them.