Rationed NHs provision for those older than normal pension age would solve the deficit in an instant. It's pretty much what NICE are up to anyhow.
A more acceptable first step would be to rationalise the "postcode lottery". For example;
My very elderly mother receives injections every month for macular degeneration. The "lottery" means she must pay £50 a time to get to the hospital and back, 40 miles away. Frankly ludicrous for someone on their own and essentially blind.
If she lived here, the NHS would send a taxi, but not pay for the injections.
Which to standardise across the country? That is the question for politicians and what they're paid for. But both "savings" are deemed broadly acceptable by politicians of the same colour. It would certainly raise the profile of the gross waste in public services, and perhaps persuade Parliament to consider outlawing deliberate waste in MoD. That waste, and the certain knowledge most of it can be avoided, is what makes the Treasury right when seeking to cut our budget. Trouble is, they don't apply the same rules to the NHS, so their waste is even worse.