The government is to look at loosening restrictions on the foundation trust private patient income cap.

Health minister Mike O’Brien last week published a call for evidence to inform a review of the cap, saying the government recognised there were “concerns” about how it operates - in particular that it does not operate evenly. For example, the document highlights that caps range from zero to 30 per cent.

One of the chief “level playing field” concerns has been for mental health foundations, which all have a cap of zero. The consultation paper says an amendment to the current health bill, giving all mental health foundations a cap of 1.5 per cent, will address the “anomaly” pending the outcome of the broader review.

The consultation calls for proposals on alternative rules which would allow foundation trusts to take on private patients but ensure they protect and prioritise NHS patients. It also sets out five principles for any new formulation, including “no cross subsidy of private care with public money”.

The cap was seen as a crucial concession to Labour MPs concerned that NHS patients might take second place to more profitable private patients when the act establishing foundations was debated in 2002.

Last year foundation regulator Monitor admitted it had been “too permissive” in its definition of the cap. It is awaiting the ruling of last week’s judicial review into its interpretation.