Jim Mackey has said NHS trusts are “trying to not blink” amid standoffs with locum doctors, agency nurses and private contractors over new tax rules introduced by HM Revenue and Customs.

The IR35 regulations, which are due to take effect tomorrow, force “off-payroll” workers to pay the same level of tax as substantive employees, by making employers responsible for paying their tax and national insurance.

HSJ reported yesterday that locum doctors and other contractors at some trusts had demanded significant uplifts in their pay and threatened not to come to work.

The NHS Improvement chief executive told HSJ: “Honestly, I think most of the noise is planted by the people who are personally going to financially benefit by us saying we’re not going to do it.

“We’ve got a small number of places that are talking to us and saying this is going to be a bit difficult. We are trying to hold our nerve and not blink, but safety will drive the decisions.

“There was an example over the weekend where there was a very organised campaign amongst the doctors to say ‘let’s make this really hurt and threaten very hard and see if we can break it’.

“I don’t know how they’re on the register as doctors – if that’s doctor behaviour, I don’t know how that will work. That will get fixed this week. The trust are saying we don’t want to break this because there’s some other bad behaviour going on among those doctors, we need you to help us hold the line.”