Labour could have done things better (far too many public sector reorganizations to which all governments seem prone) but things were really pretty awful in the NHS in 1997 with long waiting lists and crises every winter.

The public sector employment figures on page 13 of this report are pretty telling: https://www.ifs.org.uk/bns/bn145.pdf

1991-1997: NHS headcount static at 1.2M under Tories

1997-2010: NHS headcount grows to 1.6M under Labour

2010-2013: NHS headcount begins falling under Tories

One of the things Labour has done pretty well in the past is to bloat out the government with bureaucracy and paper-pushers so they can point to the total number and say "employment increased" or "the NHS is expanding" while throttling the capability of the organisation to perform its function effectively. Part of the reason the NHS is in the situation it's in now is that the ratio of front-line medical workers to administrators and managers has shifted over time (https://www.kingsfund.org.uk/projects/general-election-2010/...). There's also the case of a number of IT projects that have been extremely expensive and/or have failed disastrously, and increases in regulatory burden under Labour.

Headcount is generally not a good metric to measure productivity or effectiveness as it's a number that politicians love to manipulate to for their respective ideologies (social welfare expansion for the left and budget restriction for the right).

The figures you link to show very little to no change in staffing proportions between 1999 and 2009. Professionally qualified clinical staff sum to 52% in both years, increasing exactly in line with total NHS employment.

Figures I found for 1997 and 2007 are similar, showing proportions of clinical staff at 49% and 51% respectively. http://content.digital.nhs.uk/catalogue/PUB00829/nhs-staf-19...

And medical school intake has risen from 3,749 in 1997/98 to 6,262 in 2012/13 - a rise of 67.0 per cent. http://www.nhsconfed.org/resources/key-statistics-on-the-nhs

It's still not enough - Britain spends maybe 2% GDP less on healthcare than other rich European countries. But at the end of Labour's time in power, there were 1/3rd more doctors and nurses employed by the NHS. The funding increase helped enormously.

Edit. But yes, the massive IT projects in the NHS were a hugely wasteful like all massive government IT projects. The approach of the Government Digital Service seems to be a huge improvement.

New Labour put in all the ground work, and the Conservatives ran with it.

Building lots of infrastructure under Public-Private-Partnerships - built up massive bills - brought in under the Conservatives, massively expanded under New Labour.

The internal market, a new Labour innovation, brought in massive inefficiencies, and private profits along the way.

The current government is battering a massively weakened system.