That's a marginal tax rate of 60%. This means that there's suddenly an extra tax band created for anyone earning between £100,000 and around £113,000.
The UK tax bands now go:
Income Band Effective Tax Rate
£0 up to the personal allowance: 0%
Personal allowance up to £37,400: 20%
£37,400 up to £100,000: 40%
£100,000 up to £112,950: 60%
£112,950 up to £150,000: 40%
£150,000 and above: 50%