It is a 60% marginal rate Rich.
You lose £1 of personal allowance for every £2 you earn. So for every £2 you earn an extra £1 is being taxed at 40%. which means that for every £2 you earn you pay an extra 40p tax. That is on top of the 40% tax you are already paying. Which brings you to 60%
And yes, the crazy thing is, when you hit 125k, anything you earn over that is taxed at a lower rate.
So either earn £199,999 (there is a massive pension cliff edge at £200k) or £99,999. The worst thing to do is do overtime in the £100-125k zone as you get taxed at 60% plus 2% NI