The sons of a man who died after treatment by an overseas doctor have urged changes in the running of out-of-hours services.
David Gray, of Manea, Cambridgeshire, received 10 times the normal dose of diamorphine from Dr Daniel Ubani, who admitted being exhausted and only having a few hours sleep before starting work. It was the German doctor's first out-of-hours shift in Britain.
Mr Gray's sons, Stuart and Rory, have now condemned "systemic failures" in the UK health system following the death of their father in 2008.
"The circumstances around the tragic death of our father have highlighted numerous systemic failures in both the UK and German health systems as well as deficiencies in current European law," they said.
An inquest is expected to close and a review into out-of-hours care, ordered by the government, is to be published.
A Care Quality Commission (CQC) report last year said primary care trusts (PCTs) across England may not be effectively monitoring out-of-hours performance and risked failing to spot patient safety concerns. It examined processes at the private firm, Take Care Now, which hired Mr Ubani, and which has contracts with several PCTs.