If you have the minimum requirements I don't see any reason why you will not be in with a shot of gaining employment, as long as you are 45 yrs or under with 1500 hours plus 500 jet or 1000 turbine.
I don't think there are many 757/767 guys knocking about in the uk at the moment, but Britannia is no longer really a British airline anymore and I am sure there are a few 757/767 guys in Europe who will be applying and will more than likely get the job, but I don't think Britannia is recruiting a large number of F/O just a couple.
The fact that Britannia is recruiting and is one of the major airlines is very good news indeed, it shows that maybe the market will not take as much of a dive if war breaks out in Iraq