We need to have an honest discussion about what we want from the NHS, and what we are all willing to do to secure it. At the moment we have a choice between a Conservative Party who will fail to fund it properly and a Labour Party who will borrow money we can't afford. Neither situation is tenable.
We could also tax the rich 100% and it would still not meet the increasing running costs, and healthcare tourism is not the drain some would say it is, and certainly not when set against foreign workers in the NHS. This arguments are just playing in the margins and won't solve the problem. No party ever gets a whiff of power without our say so, and we will in general be resistant to raising of taxes. Which is what ultimately needs to happen, if we want an NHS that is free at the point of use.
The only other thing I can see working is simultaneously raising charitable donations to meet the shortfall, whilst simultaneously trying to limit our own choices that can lead to negative health outcomes. Quitting smoking, reducing alcohol consumption, eating healthily and excercising regularly would all make massive differences.
Unfortunately at present we seem collectively willing to do very little of the above to actually sort the problem, and we seem unable to cross political lines to address the problem in the way it requires. We got the NHS in the first place through reaching a national consensus, and fixing it will require the same.