This is why I love my air tools
I almost invested in an electric powered impact gun rated to 450Nm this month, ran out of funds though.
In other news...
SUCCESS!
Managed to get the fecker off by taking the wheel off, sticking the wheel nuts back on, getting my missus to hold the brake on and undid it with the big bastard 1/2" drive bar!
It deflected too much with the extension bar on so I thought I'd try it like that and it worked. I'll remember this method for next time!