David Cameron: Offa's Dyke is 'life and death' divider
Prime Minister David Cameron said Wales was witnessing a "national scandal" as Offa's Dyke "has become the line between life and death".
Addressing the Welsh Conservative conference in Llangollen, Mr Cameron said the healthcare workforce were being "woefully let down by Labour".
He criticised Welsh Labour on education and the NHS, saying patients were waiting too long for heart scans.
He said Welsh Labour was guilty of "appalling, inexcusable complacency".
"One in seven people in Wales is on an NHS waiting list," he said. "A cancer drugs fund is in England - but not here.
"I tell you - when Offa's Dyke becomes the line between life and death, we are witnessing a national scandal."
He said families had seen loved ones waiting too long for treatment - and they were "sometimes dying".
"After this utter shambles Labour should never dare call themselves the party of the NHS again," he said.
"Welsh Conservatives are arguing heart and soul that it doesn't have to be this way... with real courage and reform, things can be different."
Mr Cameron insisted the Tories were arguing for more funding, more transparency, more power to doctors and nurses.
It comes on the day a key report said NHS funding cuts may be behind longer waiting times but Wales was not lagging behind the rest of the UK.
He also talked about education, saying it was a "competitive world, it's not softer subjects and 'experimental' teaching these children need".
"It's proper spelling in English, basic arithmetic in maths, the best of our history, proper respected exams," he said.
"It's not more of this failed, left-wing, ideological clap-trap we need... it's more rigour, more standards, more choice, more hope."
Mr Cameron said his party was ambitious for Wales and insisted the Conservatives' long-term economic plan was working.
He said Wales was now the "UK capital for jobs growth".
He also said the Conservatives had agreed to the largest investment in Welsh railways since the Victorian era, including electrifying the mainlines to Cardiff and Swansea.
During his speech Mr Cameron said he believed in devolving income tax. He has already offered such powers subject to a referendum.
He told delegates he would like to see the Welsh government being more responsible for raising the money it spent.
Earlier, UK Health Secretary Jeremy Hunt launched his strongest attack on the NHS in Wales claiming it is "sleepwalking to a Mid Staffs tragedy".
Mr Hunt criticised Wales' record on waiting times and ambulance targets.
He admitted things can go wrong.
"In a system as big and complex as the NHS things do go wrong," he told the conference.
"But if you ignore the evidence when individual problems pile up, if you stick your head in the sand and pretend all will be fine... well, that's exactly what happened at Mid Staffs under the last Labour government in England.
"And that is what the Labour government in Cardiff is risking right now in Wales.
"They are sleepwalking into a Welsh Mid Staffs tragedy and unless we shout loud enough - alongside brave campaigners like Ann Clwyd, Gareth Williams and others who tragically lost loved ones in Welsh hospitals - these appalling lapses in care will repeat themselves time after time."
It is not the first time Mr Hunt has criticised the NHS in Wales.
In February, he claimed patients were suffering because Labour Welsh ministers were not investigating high death rates in hospitals.
Mr Hunt called it a "tragedy" that the Welsh NHS was not adopting reforms introduced in England since the Stafford Hospital scandal.
Since he made the statement a new version of Welsh hospital death rates has been published, which takes into account differences between Wales and England.
Figures from six hospitals with above-average death rates are being reviewed by an independent expert, to establish whether they need further investigation.
Later, Welsh Conservative Shadow Minister for Health Darren Millar encouraged a standing ovation for a mention of Labour Cynon Valley MP Ann Clwyd.
Ms Clwyd has been a vocal critic of the Welsh NHS.