There have been some very thought-provoking posts for which I thank you all. It has made me reconsider. I now think we should not muddle up the funding of the NHS with NI. NI was and is a National Working Age Insurance that should end at State Pension Age.
I believe (until someone persuades me differently) that we need a separate National Health Service Insurance (NHSI).
The working-age paying NI - workers and employers - are already paying, from their NI, an amount covering 20% of the NHS costs. For those of working age paying NI, it should go down by the amount relevant to the NHS. They would then pay that amount into an NHSI "fund". So, they are paying the same amount as before. Doing this would separate the NHS from the NI account.
Those on sufficient income, past SPA (State Pension Age), would pay an equal amount into the NHSI fund as someone of working age. I would guess that, at this point, it could be about 20% of the NI amount. However, I would also imagine that it is not that easy, but it's as good a number as any to test this. However, these are very, very rough figures.
Someone on £30,000 a year salary would pay £2,666 in NI. We can say (for argument's sake) that 20% of this would now be paid to the NHSI fund. The SPA person, also earning £30,000 income, would contribute the same to NHSI - about £533 per annum.
Remember that this is just the start. The next thing would be to move the money for the NHS that comes from taxes and goes into the NI fund, into the NHSI fund. Doing this will not affect any taxpayer. It would be an on-paper government move. Taxpayers will pay the same it will just be allocated differently.
At this point, the working-age person will be paying a lower NI and a new NHSI insurance. The total of these would equal what the old NI would have been. They will be paying the same tax and insurance as before.
The SPA person would also be paying the same tax (if any) as before. As with the work-age person, some will be differently allocated and go to the NHSI. The SPA person will be paying the newly created NHSI insurance. This could be, using our test figures, about £533 pa on an income of £30,000.
At this point, we could see what is available for the NHS and where it comes from. It will be slightly more (the SPA people's contributions) than it was previously.
Governments will have to convince us should they want to increase this and why. Any increase would come from both working-age and SPA citizens through NHSI insurance.