The restaurant has been downgraded to a one-star rating in the 2019 Michelin Guide Great Britain and Ireland, which was announced today (1 October). It was one of 18 restaurants to lose a star.
Wareing won two stars for the restaurant in 2007 in its previous life as Gordon Ramsay’s Petrus at The Berkeley. He took over ownership of the site and changed its name in 2008, before relaunching it as Marcus following a renovation in 2014.
Le Champignon Sauvage in Cheltenham also lost its second star, which it has held since 2008.
Its owners David & Helen Everitt-Matthias said in a statement: "Our lives have revolved around Le Champignon Sauvage since we opened over 31 years ago, and whilst we are hugely disappointed at loosing a Michelin star, we ultimately cook for ourselves and our guests.
"Our bookings have always been very healthy and repeat business consistently high, and so it is to our loyal customers, friends, chefs and industry colleagues that we extend a very heartfelt thanks for their loyal and continued support."
Devon’s Gidleigh Park lost its two star rating following the departure of chef Michael Wignall, but it won back a single star for 2019 under new chef Chris Simpson.
Other high-profile single star losses in London included Outlaw’s at the Capital - which has seen chef Tom Brown depart to open his own restaurant Cornerstone - Jamavar in Mayfair and Lima Fitzrovia.
Scottish country house hotel Boath House asked to be stripped of its star in 2017 after claiming the expectations of the guide were "at odds with achievable profit margins", but it was not removed from the guide until this year.
The full list of deletions as listed by Michelin are as follows:
Two star losses
Marcus, Westminster
Gidleigh Park, Devon (new chef gains one star)
Le Champignon Sauvage, Gloucestershire
One star losses
LONDON
Ellory, Hackney (closed)
HKK, Hackney (closed)
Outlaw’s at the Capital, Chelsea
Amesta, Belgravia
Jamavar, Mayfair
Tamarind, Mayfair (closed)
Lima Fitzrovia
ENGLAND
Royal Oak, Bray
Butchers Arms, Eldersfield
Harrow at Little Bedwyn, Marlborough
JSW, Petersfield
Box Tree, West Yorkshire
SCOTLAND
Albannach, Lochinver (closed)
Boath House, Nairn
Martin Wishart at Loch Lomond, Balloch (closed)