Whoa, I didn't think we were talking about busting FTLs - I thought this discussion was about working practices which are more restrictive than CAP371.
And I really don't follow this argument about the CAA not liking crews being based at two airports for long-haul ops. The criteria for ground positioning before and after duty are clearly laid down in CAP371 and I'm sure there are a number of precedents of airlines having long-haul crew bases at more than one UK airport!