No, I was wrong. According to the Norma link above, the 90gr factory load at 2428fps yields 1178ft/lbs, so fails to meet the minimum in England for roe (6mm and 1700ft/lb). According to my arithmetic (could be wrong at this time of night!) that means that a 90gr .243 must be travelling at 2917fps to meet the minimum.
It would not be legal in Scotland either due to it's low velocity (easily remedied in this case) as the minimum is a 50 grain bullet AND 2450fps AND 1000ft/lbs (in reality, to use a 50gr bullet it would need to be launched at 3002fps).
Of course we all know that the 6x70R would work very effectively on deer this size, but technically you would need to hunt outside England and Scotland, which is a pity as we have some very nice bucks!