I think he's paraphrasing- and that's a generous interpretation.
If you want an alternate 'paraphrasing', I assume he's referring to Streeting saying that lack of investment, and the failures in the NHS, is costing the country money.
If people can't work because they're ill, waiting for an operation, or can't get support with their mental health, then that's not good for them, and not good for the country as a whole. Getting the NHS working, and improving the nation's health, will mean more people are able to work.