Ed Miliband will put the health service at the centre of Labour's campaign over the summer and began by accusing David Cameron of dodging questions about increased waiting times in hospitals.
On Wednesday, Miliband used all his questions at PMQs to attack the prime minister for his "top down reorganisation" of the NHS. A source close to the Labour leader said the party was "determined to use the NHS of the centrepiece of the summer campaign".
"It's a unique valued and hugely important institution to the British people. It has seen a significant deterioration since 2010. This is about raising it up as an issue during the summer given its huge importance to the British people," the source said.
The source said the party had done a huge amount of work on the NHS since 2010 but it was "fair it say it hasn't been particularly noticed" or reported. "We want to do more on the NHS. We are trying to give it a greater weight and a greater importance."
The party also denied suggestions it had decided to move its focus away from the economy onto the NHS and pointed to a series of economic announcements made in recent days.
Labour has matched the government's spending plans for 2015/16. But Miliband will highlight the "Cameron effect" being felt in hospitals following the coalition's controversial reorganisation of the health service.
The NHS has traditionally been a strong point for the Labour Party, however Cameron has attempted to neutralise it as an issue in the lead up to the May 2015 general election. The prime minister frequently points to problems in the Welsh health service, which is administered by the Labour administration in Cardiff, as evidence that Miliband can not be trusted with the English NHS.
Speaking during prime minister's questions today, Cameron said: "The fact is Labour is in charge of the NHS in Wales and they haven't met a cancer target there since 2009."
However Miliband said Cameron was wrong. "We know why he wants to talk about Wales, he can not defend his record in England," he said. "It's this party that created the NHS and every time we have to save it from that lot opposite."