On May 30, 11:50*am, Andy wrote:
They would have to order some more units, but that wouldn't be a
problem in the short term. The Class 172 would be leased to another
TOC if this were the case and my understanding is that was why they
have the internal layout that they do. It was also one of the reasons
that they were directly leased from Angel Trains, rather than the more
complex ownership history of the class 378s (originally ordered by TfL
directly).

If the Croxley link came to pass the 172s could be easily redeployed
to provide the Watford to Aylesbury shuttle service. No need to change
the lease. It would also be possible to outsource the maintenance to
Chiltern who operate similar stock.