If, when the time comes, you leave a share of your worldly wealth to your local NHS, that’s entirely up to you. After all, it’s your money.

Whether you wish it to go to the kind nurses on Acacia Ward, or the mental health outreach team, or to fund a new reincarnation unit by the hospital mortuary, the trust board, as trustee of charitable funds, is bound under charity law to honour your intention.

Board members will invest your money separately from the trust’s main (“exchequer”) funds, and account for it separately, because that’s how charity law works. They also have a duty to spend it promptly, unless you create a long term (“endowment”) fund, such as an annual bursary for training. If they don’t, the Charity Commission will be on their case.

There is some small print but these are the basic principles.

However, two significant moves are afoot. One is a Treasury plan to consolidate the charity accounting with NHS exchequer accounts from April 2013, bringing an extra £0.5bn on to the public sector balance sheet. It will affect over 90 per cent of NHS charitable funds.

This proposal has drawn strong opposition. The Charity Commission views it as “a form of nationalisation of the gifts and donations of the public”. Sue Slipman of the Foundation Trust network warns that it could undermine people’s willingness to give.

There’s enough temptation already for NHS boards to use charitable funds to offset unpleasant cuts. There’s a real reputational risk in using donations to replace what has hitherto been government funded.

So the second current initiative is a ministerial review of governance arrangements of NHS charities, with a view to reducing the dominance of NHS board directors. A healthy enough purpose.

Yet a key aim of this review, says the Department of Health, “will be to ensure that current and future charitable funds remain protected in the sole interest of patients”.

Let us hope not. The aim must be to ensure that the wishes of those who make legacies and bequests are inviolable. Not least because otherwise a valuable source of funds may quickly evaporate.