The government must set out plans for an inquiry into its handling of the coronavirus pandemic, the health service ombudsman has said.
This was not about blaming staff but about "learning lessons", he said.
Ombudsman Rob Behrens said patients were reporting concerns about cancelled cancer treatment and incorrect Covid-19 test results.
Ministers have not committed to holding an inquiry, but have accepted there are lessons to be learned.
The Parliamentary and Health Service Ombudsman (PHSO) stopped investigating complaints against the NHS on 26 March, to allow it to focus on tackling the Covid-19 outbreak.
But people had continued to phone in with these concerns, Mr Behrens said.
And cancelled treatment and wrong coronavirus test results have emerged as major themes.
"Complaining when something has gone wrong should not be about criticising doctors, nurses or other front-line public servants, who have often been under extraordinary pressure dealing with the Covid-19 crisis," he said.
"It is about identifying where things have gone wrong systematically and making sure lessons are learned so mistakes are not repeated."
Mr Behrens said he had written to the government on 19 May asking for information about the scope of any future inquiry, but had not received a response.
Hearing the real experiences of people who used NHS services during the pandemic should form part of any future review of the government's handling of the pandemic, he added.
And an "independent, swift and urgent" review could have an impact on policies should there be a second wave of infections.
He said while the government still needed to focus on the current crisis, there were already themes "that we can learn from".
"You can do both things," he said.
Last month a group of leading scientists and medical experts wrote to the government, demanding an urgent public inquiry into the response to Covid-19. They warned that without it more lives could be lost if there was a second spike in cases.
Relatives of 450 people who have died in the pandemic have also demanded an immediate public review to minimise the continuing effects of the virus, ahead of a full inquiry.
And number of MPs have said they will form a cross-party parliamentary group in support of an urgent inquiry into the government's handling of the crisis.
During an evidence session to MPs on Tuesday, patients described problems they had had because of cancelled care.
Knee-surgery patient Rob Martinez said he had not heard anything from his doctors.
"It just went so silent. I was so close to having it and then it got cancelled and it was absolutely devastating," he said.
Daloni Carlisle said: "My doctors toRead More – Source