The new government has made tackling NHS waiting times a key priority - and this week appointed NHS surgeon and former health minister Lord Ara Darzi to investigate what is going wrong . Is productivity the place to start? The scale of the challenge facing Health Secretary Wes Streeting was made clear as he announced the review on Thursday. The latest performance figures – the first published since the election - showed the hospital backlog had risen again for a second month in a row, hitting 7.

6 million. The British Medical Association called it a "shameful" legacy for the Tories to leave. In its manifesto, Labour insisted it had a plan to tackle this - creating an extra 40,000 appointments and operations a month, by getting the NHS to do more at weekends as well as using the private sector more.

It has pointed to hospitals in London and Leeds that have had great success in doing weekend working, which has allowed them to improve efficiency through high-intensity use of operating theatres. Surgeons carry out the operations across two theatres with one being used to operate on the patient, while the next patient is readied in the other. But these are the exceptions.

If you look across the entire NHS, hospitals have actually struggled to increase activity despite more money being invested and more staff being employed. Compared to five years ago, spending after inflation has risen by nearly a fifth and the workforce by nearly a quarter, yet the number of patients starting tr.