Ed Miliband has visited a cricket club in Nuneaton to launch Labour's new election campaign posters on the NHS.
He told supporters that the IFS assessment of party manifestos showed the Tories were committed to "extreme spending plans" that would "end up cutting the NHS".
Labour has accused the Tories of planning the biggest spending cuts in any of the world's advanced economies since the Second World War.
Ed Miliband warned the Conservatives plan to balance the books would result in 20,000 fewer police officers and the closure of 1,000 sure start centres.
He will tell a rally in Leeds: "It is a plan so extreme that International Monetary Fund figures show Britain would be facing the deepest cuts over the next three years of any advanced country in the world.
"It is a plan so extreme that far from protecting the NHS they would end up cutting the NHS. It is a plan so extreme that it wouldn't mean three years of the good life, it would mean three years of hard times.
"Maybe not for some of the rich and powerful, who have done so well with the last five years of the Tories. But it would mean hard times for the working families of Britain, who put in the hours, pay their taxes and play their part."
Jeremy Hunt has compared modern politics to dating app Tinder and called for a return to old-fashioned doorstep canvassing.
Both of the men with a chance of being PM has something they're not telling you. It's about the way they plan to fund the whole NHS.
Labour will pledge more cancer tests to be carried out by family doctors and new equipment to help treat sufferers.