A promised pay rise for NHS workers under a Labour government that would cost billions would be paid for by putting up taxes on big business, the shadow health secretary has said.
The party would lift the 1% cap on salary hikes to give a boost to staff who have been "undervalued, overworked and underpaid" by the Conservative Government, Jonathan Ashworth said.
Labour says it will also legislate to require NHS trusts to have regard for patient safety when setting staffing levels, as "Tory mismanagement" has left the health service "dangerously understaffed".
But increases on the wage bill to take account of inflation, which has reached 2.3% but is predicted by to hit 3%, would costs billions of pounds.
Mr Ashworth said corporation tax, which has been cut to 19% from 28% under the Conservatives, would be used to cover the costs of the increased wage bill.
He told BBC Radio 4's Today programme: "I would want NHS staff to get a rise which takes account of the cost of living.
"We believe that some of the big cuts in corporation tax, some of the big giveaways to very big corporations that have gone on under the Conservative government and will continue to go on if the Conservatives are re-elected do not need to go ahead.
"We are asking those with the broadest shoulders to contribute more.
"We will outline what level corporation tax will be in our manifesto when we publish it in the coming days."
Mr Ashworth insisted the plans were credible despite Labour having said it would use corporation tax reforms to fund changes to the adult skills budgets, help for the steel industry, reforms of maintenance grants, the scrapping of university tuition fees and boosts to pensions, social care and the schools budget.
"The whole programme that the Labour Party will be putting to the country in this election campaign will be costed," he insisted.
Paul Johnson, director of the Institute for Fiscal Studies, told Today: "Each 1% on pay, just 1%, costs half a billion pounds each time. It's not possible to say from what the Labour Party have said quite how much more they intend to spend on the NHS.
"If you are going to do that over the next two or three years you will also clearly need to raise significant extra sums in tax revenue."
Health Secretary Jeremy Hunt said he would like to see NHS staff receive an increase in their pay packets.
He told ITV's Good Morning Britain: "I would certainly agree NHS staff do a brilliant job and we would certainly like to pay them more than we are able to at the moment [but] we have had to face a very difficult period financially."
Pressed on whether he had accepted an increase in his salary as an MP, he replied: "Ministers have actually given themselves a pay cut - that's the only pay we have control over.
"I have accepted my pay rise as an MP and my pay cut as a minister and that's the point: all ministers have done because we recognise we have to set an example."
Labour says will ask the National Institute for Health and Care Excellence to assess whether legally enforced staffing ratios should be introduced in some health settings.
The party would also reinstate funding and support for students of health-related degrees and incentivise NHS jobs to boost staffing levels.
Jon Skewes, of the Royal College of Midwives, said: "This announcement also shows recognition of the folly and short-sightedness of scrapping bursaries for student midwives, nurses and related professions.
"We would now want to see all parties making similar commitments to pay NHS staff fairly, and staff and resource our NHS so that it can meet the demands being placed on it."
TUC general secretary Frances O'Grady said: "Under the government's current plans, NHS workers will lose thousands of pounds from their salaries. This is unfair, it will demoralise staff and it will increase the number who decide to quit.
"We hope all the parties will make an election pledge to scrap the unfair pay restrictions and give our hard-working NHS staff the pay rise they deserve."
Unison general secretary Dave Prentis said NHS staff are "struggling to get by" on below-inflation pay rises and lifting the 1% cap would make them feel valued.
"A decent wages increase would also help ease the crisis in staff recruitment," he said.
"There are too few nurses, paramedics and midwives in the NHS to deliver the best care, and this is putting patients at risk."