Five trusts have achieved foundation status today, meaning they have more autonomy over their finances and their clinical priorities.
According to Unison, rules set out by Foundation Trust regulatory body Monitor contain a loophole that allows them to carry out unlimited amounts of private work by setting up joint ventures with private sector companies.
Karen Jennings, Unison head of health, said: ‘There are very sound reasons for the cap on private patient income. Without it there is a danger that the treatment of NHS patients will come a poor second to cash-paying private patients.
'UNISON believes that Monitor’s interpretation of the law is wrong. As a result we think Foundation Trusts are likely to be under-reporting the true amount of money they receive which goes towards their private patient income cap.’