I used to go 40 mph in my toyota corolla diesel as that was the magic number for FE, people went crazy behind me!If they want to take a risk over taking stupidly that's also their problem.Just go a slower route and they can over take in a safe place.
After all if they have an accident the police aren't going to prosecute you for dangerous driving it's the idiot overtaking who's gonna get it...NO matter how mad they were about you going slower!
Don't you think that attitude is rather rude and selfish? If you're going slower than prevailing speed (or slower than the speed limit) and holding up traffic because passing is unsafe, it is your responsibility (maybe not legally mandated, but your responsibility nonetheless) as a road user to be a nice guy and let folks pass...
Oh, and you're probably ruining my P&G/EOC by putting along at 40mph on a 50mph road.