From an article about this on The Guardian the other day, I noticed the following mentioned:
"Some IT workers might work for a company for a short period or they might work for multiple companies at the same time. In that case they would not be seen as an employee."
So I take a 6 month contract with Company A and every 28 days (preferably on a weekend) I do a short-term contract for my Agent's company lasting 1 day (billing a nominal £1 for "consulting" and not requiring any on-site presence). Because I am working multiple concurrent contracts, my understanding is that it will not be a requirement to go on to the payroll for Company A.
I think we can all agree that there will always be loopholes.