Conditions in the NHS are "familiar" to those found during the Mid Staffordshire scandal, according to the lawyer who chaired the inquiry into the hospital trust.
Barrister Sir Robert Francis QC, whose 2013 report uncovered poor care in Mid Staffordshire, said the pressures the health service was under were "pretty bad".
It comes after a week of scrutiny of the NHS, with performance figures showing a raft of missed targets and record waiting times, leading the Health Secretary Jeremy Hunt to say conditions were "completely unacceptable"
Sir Robert told the BBC's The Andrew Marr Show: "I think they are pretty bad. We've got a virtual storm of financial pressures, increased demand, difficulties finding staffing, and pressure on the service to continue delivering. And some of that sounds quite familiar, as it was those were the conditions pertaining at the time of Mid Staffordshire.
"Things have changed since then, so the very fact that we're talking about this today the way that we are, the very fact that the Secretary of State says things are unacceptable, shows that there's a greater level of transparency.
"So people are talking about the problems in a way that they weren't before. But the system is running extremely hot at the moment and it's only working at all because of the almost superhuman efforts of the staff of the NHS, and it can't carry on like that indefinitely without something badly going, or risking going badly wrong."
He said there were now better safeguards in place and problems should be spotted before it reached the proportions of the Mid Staffs scandal between 2005 to 2009, during which time as many as 1,200 patients may have died after they were "routinely neglected".
Sir Robert, a non-executive director at the Care Quality Commission, said more funding would be a "sticking plaster" and there needed to be a change in the way the service is delivered, as well as addressing the adult social care crisis.
Figures emerged last week showing that numbers of A&E patients seen within the target of four hours fell to a record low of 86% in December, while those waiting longer than 12 hours to be admitted to a hospital bed doubled to more than 2,500 in 2016.
The number of people waiting more than two months to start cancer treatment after an urgent referral was at a record high of 25,157, and the proportion of patients receiving hospital treatment within 18 weeks fell below 90% for the first time since 2011.