Those reroutes mean Italy oceanic departures, Swiss-UK arrivals, UK-Cyprus departures etc all route through Clacton Sector. This means longer delays for those aircraft which habitually route through Clacton. Clacton took a pounding all afternoon yesterday (not forgetting that NSEA was open on only one position all afternoon as well due staff shortage).
When will it improve? You might well ask.
There were however plenty of suits (from CE downwards) ambling around the Ops room yesterday. Perhaps they were seeing what it's really like before the result of the pay ballot is announced later in the week...