Your editorial (comment, page 19, 22 June) is right to point out that the NHS's founding principles are not simply the sacred cows of an outdated ideology but an essential means of providing efficient and equitable healthcare.

The World Health Organisation has praised the UK health system because, relative to many other countries, it is fair and gives good value for money. The fact that the NHS provides healthcare largely free at the point of use, funded from general taxation, makes it an extremely efficient form of pooling risk and of promoting social justice. That is not to say that the NHS is perfect. But that is no argument for undermining the foundation stones of the service by charging people for seeing their doctor or by reducing its scope and enabling the private sector to replace it in many areas of care.

Undermining the principles that underpin the NHS, though attractive to some people, would have serious consequences.

We would probably spend more on health, but get less value. We would exclude the very people who need health services most, exacerbating the inequalities that already cause so much unnecessary ill-health. Some sacred cows may actually be worth keeping.

Rabbi Julia Neuberger Chief executive King's Fund