Around 1,000 workers have been made redundant after celebrity chef Jamie Oliver’s restaurant chain collapsed into administration following failed attempts to secure additional investment.

Jamie’s Italian has appointed KPMG as administrators, the company has confirmed, and 23 of the brand’s 25 sites have closed.

HSBC, which is the company’s main bank lender, is facing a multi-million-pound loss following the restaurant chain’s collapse.

Oliver said: “I am deeply saddened by this outcome and would like to thank all of the staff and our suppliers who have put their hearts and souls into this business for over a decade. I appreciate how difficult this is for everyone affected.”

The firm closed 12 of its 37 Jamie’s Italian branches as part of a company voluntary arrangement (CVA) in 2018.

Oliver, who established the Italian food chain in 2008, has pumped £4m in to the business since the beginning of this year to support additional fundraising, but none was forthcoming.

Will Wright, partner at KPMG and joint administrator, said: “The current trading environment for companies across the casual dining sector is as tough as I’ve ever seen.

“The directors at Jamie Oliver Restaurant Group have worked tirelessly to stabilise the business against a backdrop of rising costs and brittle consumer confidence.

“However, after a sales process which sought to bring new investment into the business proved unsuccessful, the team took the incredibly difficult decision to appoint administrators.”

Oliver’s three restaurants at Gatwick Airport will remain open while administrators explore options for the sites, and the international branches will continue to trade as normal.