Proposed airlines wanting to start-up in the UK that I know of:
Air Tigra - Nottingham EMA based B767 operator
Birmingham European Airways - The J32 operator which has already been mentioned in this thread (are also evaluating the Saab SF340)
Exxavia - will operate 2x A320s on behalf of Irish tour operator Aviajet
GCI Airlines - Proposed routes linking Guernsey with BHX, EDI and LBA, possible Do328Jet fleet, at feasibility stage.
Global Spirit Airlines - Boeing 742 operator
Tara Airlines - to be based at LTN, chasing an ex Etihad A332
Most dead in the water, my money is on BHX EU Airways and Tara Airlines to survive - for at least a year anyway.