It may seem to some that a lot of people are trying to get back to the UK but there is also a huge amount of talk and no action. This goes for all nationalities. It will never change as people either think they are hard done by or just prefer to live in their native country.
Every airline in the world is looking to cut costs and we are a prime target as are all employees in any business as a major cost. So if they can increase your productivity they will. Also they will pay good money to someone who is skilled at doing so.
As far as having industrial agreements in place to protect you from the increase in FTLS,well don' forget that 97% of the workforce at VS stood up against the company for all of a few days and then got screwed by Balpa and VS. A common outcome these days in our industry. I can't see your chances being any better if you try to fight FTL changes within VS. There will always be someone willing to sell themselves and go to work for a lump of cash. We have all seen it before.
Better we try to rebuff these stupid changes in FTL at source.
Thats just my 10 pence worth anyway. Good luck to you all and the grass/sand will always look a little greener/whiter on the other side, but in my experience they are all the same but different.