Not just IT
The haulage industry is watching this with interest. There's a scam whereby agency staff join an "umbrella company" that treats them as PSCs for tax and NI, For an extra £1 ph (yup, a whole pound) the driver gives up pension, SSP, holiday pay and workplace rights. Nor is he treated differently to a staffer. His workload is allocated without his input, he must protect the brand, he must comply with any reasonable instruction and his infringements are managed in-house. HMRC intend to rip this up, and there's a rumour that the agency will be made liable for unpaid revenue.
Which is why I'm PAYE.