A cross-party commission should be set up to review the future of the NHS and social care in England, a trio of former health ministers say.
Ex-health secretaries Stephen Dorrell and Alan Milburn and Lib Dem MP Norman Lamb say without radical change, the future looks bleak.
Mr Lamb will raise the issue in Parliament on Wednesday, warning that the systems could crash without action.
He said even the promises of extra money for the NHS were not enough.
Ministers have pledged £8.4bn above inflation by 2020.
But Mr Lamb said that would still leave the health service short with a growing number of hospitals struggling with deficits and to keep pace with demand.
And he said that was before the state of social care was taken into account. He claimed those services, paid for by councils, were on the brink with concerns that a number of care home providers were set to leave the market.
"The reality is that we will either see the system effectively crash or we confront the existential crisis now. This transcends party politics."
He said the commission should look at everything from increasing taxes - as he has pushed for - to ending the "artificial divide" between health and care.
The MP, who served as a health minister under the coalition, will call for the cross-party commission in a 10-minute rule bill - a device by which backbenchers can propose legislation.
Mr Dorrell, who is now chairman of the NHS Confederation, which represents NHS trusts, and was health secretary in John Major's government, said he supported Mr Lamb's bid.
He predicted the problems being experienced now would "only get worse" in the next decade.