The NHS has been underfunded for years. Decades.
The Tories would love nothing more than to make heath care private, but the NHS has such a special place in the heart of the public, they've never had the balls to do it. Instead, they under fund it, leading to long waiting lists for treatment, removal of services, reduced staffing etc.
Even under Labour, the NHS didn't have the funding it needed. With an ever ageing population, the cost to provide free healthcare increases.
Since I've moved to Australia, I find the health care system here far better than the NHS. You have a public system (Medicare), which provides free care to anyone. But also a private system, paid for my individuals having private health insurance.
High earners get taxed with a Medicare levy is you they don't have private insurance, so it is often cost effective to have insurance (plus you get the obvious benefits to private care, with faster access to treatment). This reduces the strain on the public system, which is far better funded than the NHS in the UK.
http://en.wikipedia.org/wiki/Health_care_in_Australia