Deputy chief executive, Kate Terroni, will be appointed interim chief executive until a permanent appointment is made.

Trenholm said: ‘During my six years leading CQC, we have made important changes to the way we work in order to help improve care and keep people safe. We are now in the final stages of delivering an ambitious transformation programme – this month saw the delivery of the last big milestone in a complex and challenging programme of work.

‘While there will always be more work to do, the conclusion of this stage of the transformation feels like a good time to move on. It has been a privilege to work with such a passionate, committed and talented group of colleagues.

‘I am incredibly proud of what we have achieved together, and I am confident that the organisation will continue to evolve to help support the health and care system to provide good, safe care for people.'

CQC's chair, Ian Dilks, said: ‘The board would like to thank Ian for his contribution to CQC over many years and for leading us towards our ambition of being a smarter and better regulator.

‘I and my board colleagues look forward to supporting and working with Kate in the further development of CQC.'