Given the existing non-trivial subsidy, how sustainable is Dundee as an airport once the Belfast and Birmingham routes are lost, particularly now that Edinburgh is under separate ownership from Glasgow and likely to be a little more nimble on its toes compared to the time under BAA.
From the 2011 CAA stats, passengers number for each route were
London City - 31,632
Belfast City - 10,071
Birmingham - 18,215
Jersey (seasonal) - 1,813
In effect, Dundee loses approx 46% of its commercial passengers on 2nd Dec. I imagine also that the Jersey route is heavily leisure centric and thus more difficult to justify any form of Govt subsidy.
In particular, it would seem that the loss of the Birmingham and Belfast passengers may necessitate a (slightly) increased Govt subsidy to keep Dundee in its current state.