France has Corsair, Spain has Air Europa, both of which do longhaul and domestic, so are similar to Virgin (or how it will be from March 2013). So not the case that they can only sustain one full-service carrier each.
Corsair is part of TUI (A Travel Agent), it is mainly a charter carrier and the scheduled destinations are tourist oriented, so I would not count it as a “Full-Service” Carrier, Also they do not serve any domestic routes, they only serve Africa and North America
Air Europa is makes a better case for being a full-service carrier however, but it’s still operarates fair number of charter routes, I would compare then to Monarch and Air Berlin
So my case still stands that France and Spain can only sustain 1 full-service carrier
Why can the UK not sustain 2 major full-service carriers?
Because times have changed since VS was formed in the 80s, the market has been deregulated and hence BA has to now compete with LCCs, carriers in mainland Europe and now Gulf Airlines, they puts a lot of preassure on margins, what maks the problem worse is that there is a lack of space to lanuch new routes from LHR, hence it is not a good idea for VS to keep operating services on routes that alresdy have competition already
VS also has a porblem with the fact it does to have enough slots to have a route network that is big enough to make it a viable alternative to BA