Oliver’s restaurants have been in trouble for several years with branches closing around the United Kingdom.

A restaurant group founded by British celebrity chef Jamie Oliver has gone into a form of bankruptcy protection known as administration, putting some 1,300 jobs at risk.

The Jamie Oliver Group, which includes the Jamie’s Italian chain, appointed insolvency administrators from audit firm KMPG on Tuesday, according to a message posted on the Jamie’s Italian website.

Oliver, whose group operates 25 restaurants in the United Kingdom, said he was “devastated” by the administration.

“I am deeply saddened by this outcome and would like to thank all of the people who have put their hearts and souls into this business over the years,” he said in a Twitter post following the announcement.

“We launched Jamie’s Italian in 2008 with the intention of positively disrupting mid-market dining in the UK High Street with great value and much higher quality ingredients, best-in-class animal welfare standards and an amazing team who shared my passion for great food and service. And we did exactly that,” Oliver said in a separate statement.

The restaurant group includes steakhouse Barbecoa and Jamie Oliver’s Diner.

A statement from the group said the restaurants will “continue to trade as normal”. However, closed notices have reportedly been posted on a number of outlets.

I’m devastated that our much-loved UK restaurants have gone into administration. I am deeply saddened by this outcome and would like to thank all of the people who have put their hearts and souls into this business over the years. Jamie Oliver — Jamie Oliver (@jamieoliver) May 21, 2019

Oliver, 43, first rose to prominence in 1999 with his television programme, The Naked Chef, which was broadcast in dozens of countries.

His subsequent shows and cookery books have helped make him one of the world’s most high-profile chefs, a reputation Oliver has used to put pressure on UK politicians to combat childhood obesity by campaigning for healthier school meals.

Oliver’s business has been in trouble for several years. The closure of the last of his Union Jacks pizza diners came in 2017 – the same year the chef poured $3.8m of his own money into his restaurants.

The Jamie magazine, which ran for almost a decade, also ceased publication in 2017.

Oliver’s restaurant chains are the latest victims of a brutal trading environment on the UK’s high streets, where rising rents and food prices – combined with increased competition – are shuttering many establishments.

In March, Boparan Restaurant Group said it planned to close more than a third of its Giraffe and Ed’s Easy Diner outlets. And last year, Carluccio’s, Prezzo, Strada and Gourmet Burger Kitchen all closed branches in the UK.