I can’t comment on ASLEF, but the RMT would prefer sufficient staffing levels and salary rates such that staff don’t have to rely on overtime or rest day working and the companies don’t have lots of unfilled vacancies.
Also, unsurprisingly, the RMT would prefer the use of railway company employed staff rather than rely on labour only contractors or contractors hired to do core or routine work. The RMT does not have a problem with specialist contractors, or occasionally the use of contractors to handle higher than normal/peak work loads.
In terms of the railways relying far too much on overtime or rest day working, read the ‘Investigation into the Clapham Junction Railway Accident’ by Anthony Hidden (QC) (
available here, far too long to quote). The excessive overtime and lack of rest by railway employees was identified by Anthony Hidden in his investigation. That’s why the railway now calls the limits on overtime working the ‘Hidden rules’.
TSSS? You mean TSSA I presume…