Looks like the fixed cup on an old Raleigh. You didn't by any chance used to have cottered cranks? Mark Stonich at Bike Smith Designs has a natty tool for just that application. It is a bugger. You can also use a hammer and an old flat head screwdriver if you can work out which of the flats to apply the persuasion to to make it turn the correct way. Or if you have access to a heavy duty bench vise, with some careful balancing, you can grip the flats and use the frame for leverage. A suitable soaking with WD40 will also help.
Looks like the fixed cup on an old Raleigh. You didn't by any chance used to have cottered cranks? Mark Stonich at Bike Smith Designs has a natty tool for just that application. It is a bugger. You can also use a hammer and an old flat head screwdriver if you can work out which of the flats to apply the persuasion to to make it turn the correct way. Or if you have access to a heavy duty bench vise, with some careful balancing, you can grip the flats and use the frame for leverage. A suitable soaking with WD40 will also help.