Its clear that the GWML is becoming a bit of a no go area on Sundays especially as this situation continues. Key questions are:
1.What are GwR doing about it?
2. Is the DfT on GwR's back to get it sorted?
I don't think anything is clear - as PHILIPE notes, today the Cotswold Line seems to have escaped cancellations - thus far at least - whereas yesterday there were so many cancellations as to render the service almost unusable.
Whether better incentives were on offer to staff to turn out today rather than yesterday, others may know, but clarity and certainty about what trains might be running on which days have been utterly lacking over the past four months or so. All it needs is for a couple of people to call in sick, or not enough volunteers to work a rest day, and that blows a hole in the timetable.
In the case of Oxford/Cotswold services, there seems to have been some issue over IET training for Oxford drivers and subsequent terms and conditions for staff based there, which has left other depots to try to cover all the services via Oxford worked by IETs. Some days that works out, other days it doesn't.
MPs have certainly been on the DfT's case but after the Southern debacle, I get the feeling there isn't a great deal of enthusiasm among DfT ministers for another trench war with the unions. Try to start a fight over making Sunday working part of contracts and there would be no trains anywhere in the country on a Sunday.
It looks as though GWR's policy is just to grit their teeth and get though to the end of the IET training programme (which in the case of the recently-created Worcester depot is compounded by the need for traction training on other types as well, depending on where staff have transferred from, plus route learning) - it should not be forgotten that GWR's IET training did not start until last September, rather than May, due to issues over use of the Didcot-Reading section for that purpose.