It will be interesting to see just how long this goes on before there is a massive climbdown by the govt/NATS/CAA/met office and business gets back to normal - the eruptions haven't stopped and the weather pattern seems set to stay.
No one doubts that flying through volcanic ash is bad for engines but at what concentration of ash does it become a factor? The 1982 incident happened in an ash cloud so dense it looked like thick 'normal' cloud - what is above most of UK and the surrounds is barely visible to the naked eye.
Since what there is of the ash cloud seems to be easily trackable by satellite and forecastable in track by the met office, why not route aircraft round the 'high risk' areas and get on with it?
We seem to be victims of an internationally agreed protocol where 'volcanic ash' seems to be the trigger for a chicken-licken 'the sky is falling down' reaction rather than accepting that volcanic ash is present in the atmosphere all the time and defining concentrations that are either safe or not to fly in.
If I was an airline boss I would be demanding some decent scientific evidence of concentration level Vs risk.