Dido Harding has confirmed she could apply to lead NHS England, and has defended her much-criticised record leading England’s Covid test-and-trace system, saying the main issue with the service was that “expectations were set too high”. Covid testing in the UK was now “the envy of the world”, Harding told BBC Radio 4’s Woman’s Hour. In her first interview since stepping down from the test-and-trace job at the start of last month, Harding confirmed she was considering whether to apply to succeed Sir Simon Stevens as chief executive of NHS England. “I’m thinking about it,” she said. “I have loved working in the NHS for the last three-and-a-half years. It’s been the privilege of my life.” Harding, a Conservative peer, has chaired the board of NHS Improvement, an oversight arm of NHS England, since 2017, but the bulk of her career has been spent in areas such as supermarkets and telecoms, notably as head of the TalkTalk group. She has faced criticism over her role in the test, trace and isolate service, but Harding argued that the bulk of this was because people started the pandemic with unrealistic assumptions about what it could achieve. “If there’s one regret I have, it that’s those expectations were set too high,” she said. “I think all of us had a lot of hope invested in test and trace a year ago. And what we’ve learned – and the world has learned this – is testing and tracing and isolating is a part of the response. It’s not the silver bullet, it’s not the only thing that means life can get back to normal.” This was the case in every other country and territory, Harding argued. “Sadly, no test-and-trace system on its own in the world has been sufficient to avoid lockdown,” she said, citing the fact that Taiwan had recently had to extend a lockdown. Critics of England’s system have argued that test-and-trace systems in other places have worked much more effectively. While Taiwan’s Covid deaths are currently rising, they remain below 250 in total, compared with nearly 130,000 in the UK. But Harding said it was unfair for people to complain that the system had not performed well. “That’s where I really do disagree. We have a testing infrastructure today that is the envy of the world. We do more tests per head of population than any other developed country in the world,” she said. Asked several times by the interviewer Emma Barnett if she felt there was anything she should apologise for over test and trace, Harding declined, again saying much of the criticism was based on unrealistic expectations. She said: “I think everyone, not just me, not just the prime minister, everyone in the country wanted to believe that testing, tracing and isolating on its own would mean that we didn’t have to do some of the incredibly horrible and unnatural things that we’ve had to do to contain Covid. I think it’s more that we’ve all learned a lot in the course of the last year.” Harding said any apology was “in the sense that I’m apologising for the science – the disease is such that it looks to be impossible to be able to contain it only with testing and tracing.” Boris Johnson’s spokesman on Monday declined to say whether the prime minster would provide Harding with a glowing reference, only saying he would not comment on an “ongoing recruitment process”. He confirmed that applications would close on 14 June. • This article was amended on 8 June 2021 to clarify that the Covid test-and-trace system formerly led by Dido Harding was for England only, not the whole of the UK.