A contractor who earns 100k in a year generates 47.2k tax (VAT, corporate, dividend, income tax and NI)
If the same contractor worked as permanent employee he\she would be paid 80k at best, because employment has additional costs as as employers NI and Pension contributions. This person would be paying 25.5k to the treasury as income tax + NI. The employer would be paying 11k per year as NI contribution.
This is a loss of tax revenue 12k to the treasury per year per contractor.
The Treasury is expecting to 3.1b revenue from this IR35 ruling do not have a clue about the tax rules.
DO not feel sorry for the contractors, feel sorry for the lost revenue to the treasury which are meant to pay for schools, NHS and Police and other services!