Following a seven-year partnership with developer and hotelier Harry Handelsman, owner of St Pancras Renaissance Hotel and The Stratford, the duo are parting ways in order for Powell to focus on opportunities more aligned to his long-term culinary vision.
Powell has already completed his final service at The Midland Grand Dining Room, where head chef Charlie Crote is now leading the kitchen team. He will remain at Allegra until his last service there on 14 July.
"To have had the opportunity to open restaurants in not one, but two of London's most iconic buildings has been a privilege and I am incredibly proud of what we have achieved, none of which would have been possible without the hard work of my brilliant front and back of house teams, both past and present," says Powell.
"Thank you to all of them as well as all of the guests over the years, many of whom have not only become regulars, but friends too. However, the time has come for me to move on and I am hugely excited for the future and my next chapter."
Under Powell, Allegra was listed in the UK's Top 100 Restaurants and last year The Midland Grand Dining Room was named One to Watch at the National Restaurant Awards. The St Pancras restaurant is ranked number 58 in the current Top 100 Restaurants list.
"I would like to thank Patrick for his hard work, talent and passion in making The Midland Grand Dining Room and Allegra the success they are today," says Handelsman.
"It's been a pleasure working with him for the best part of a decade and I wish him all the best for what's coming next."