[Osem]

http://www.bbc.co.uk/news/uk-21812596

A tax loophole that allows firms to dodge £100m a year in National Insurance will be closed under a new scheme targeting offshore payroll services...

...Mr Alexander said around 100,000 employees - mostly teachers, nurses and oil and gas workers - were believed to be paid through offshore payroll services set up in tax havens such as Jersey and Guernsey and could be ineligible for statutory sick pay, but completely unaware of that status.

It's not very clear but presumably it relates to this:

http://www.bbc.co.uk/news/uk-politics-17927792

More than 2,000 public-sector workers could be avoiding the full rate of income tax through special contracts, government research has found.

An investigation was ordered after a civil servant was found to be getting paid £182,000 without deductions for tax or National Insurance.