Fleet reduction is the short answer in 2012. Over 30 skippers, the DFO claims are not required for summer 2014 due to the fleet remaining static this year. Consequently they are being demoted in April.
TCUK is using 3 ACMI aircraft this summer instead of flying the passengers in house and blocks of capacity have been sold to Easyjet. There are a large number of Captains on career breaks to return still. Any junior F/O is wasting his/her time at TCX long term, short of massive expansion occurring.
Hope that helps.