This thread sums up my understanding of the TUPE rules and aligns with what I have actually seen happen on the N Sea over the last couple of decades:
http://www.pprune.org/rotorheads/391...-question.html
The 2014 changes to the TUPE regulation don't seem to have changed the basic premise much. A check of the guidance material available on the ACAS website shows that TUPE will apply if:
1. The employees are deliberately organised by the employer to provide a service for a particular client.
2. If the same work is being performed, with the same equipment at the same premises.
There are other criteria, but these two indicate to me that TUPE will not apply with regard to this contractual change.