HUMAN errors happen and, when they occur in the health service, there can be tragic consequences.

Such was the case with 57-year-old Diane Priestley, of Shildon, County Durham, who died after emergency call operators failed to recognise her life was under threat, resulting in a critical delay in an ambulance being sent.

It took three desperate 999 calls by Mrs Priestley's husband David before an ambulance was despatched, but even then it missed its target time.

The North East Ambulance NHS Foundation Trust has apologised to Mr Priestley and promised that lessons have been learned.

But while the human errors are alarming enough, there is a more far-reaching concern contained in the ambulance trust's apology. After explaining that the initial delay was due to a call handler's error, the trust admits that the ambulance still failed to attend within the timescale necessary once the case had finally been established as a priority.

It adds: "This was as a result of high demand on that day for emergency responses, compounded by a lack of resources to meet that demand."

This surely represents an admission that the North-East ambulance service is not fit for purpose – that it can't cope on busy days. Emergency services cannot be run in the hope that the phones won't ring too often.

With the general election weeks away, the parties are predictably falling over each other to make various pledges about investing in the National Health Service.

The tragic case of Diane Priestley underlines why those promises must be more than mere political point-scoring.