Newcastle have begun their search for a new manager amid a furious backlash from fans after announcing manager Rafael Benitez will leave the club at the end of the month.
The Magpies made their announcement on Monday after failing to reach an agreement with Benitez over a new deal, with fans responding by ramping up the pressure on club owner Mike Ashley.
Former Toon hero Alan Shearer described the decision as a "shambles", while prominent supporters' group True Faith declared it "utter insanity".
"It is with disappointment that we announce manager Rafael Benitez will leave Newcastle United upon the expiry of his contract on 30th June 2019," the club said in a statement.
"We have worked hard to extend Rafa's contract over a significant period of time, however, it has not been - and will not be - possible to reach an agreement with Rafa and his representatives.
"Rafa's coaching staff, Paco de Miguel Moreno, Antonio Gomez Perez and Mikel Antia, will also leave the club on 30th June.
"We would like to thank Rafa and his coaching team for their efforts over the last three years and their significant contribution to what has been collectively achieved.
"We would also like to thank our supporters, players and staff for their patience during a period of uncertainty. The process to appoint a successor will now begin."
Former Newcastle striker Alan Shearer reacted by saluting Benitez on Twitter, while closing his post with "#Shambles".
The future of Benitez, who has spent just over three years in charge at St James' Park since replacing Steve McClaren in March 2016, has been gathering momentum for the past 12 months.
Newcastle made Benitez a new offer but were unable to give the former Valencia, Liverpool, Chelsea and Real Madrid boss certain assurances.
Benitez wanted greater control of Newcastle's recruitment process, including the freedom to sign the players he wanted regardless of their age or potential resale value.
The Spaniard guided Newcastle back to the Premier League at the first attempt in 2017 and has kept them in the top flight for the past two seasons on a shoestring budget.
Benitez has been linked with a possible move to the Far East for over 12 months, with Chinese club Dalian Yifang reported to have offered him a contract worth STG12million ($A22 million) per year.
The club's situation is further complicated as Ashley is in talks with several potential purchasers, including Dubai-based billionaire Sheikh Khaled Bin Zayed Al Nahyan, who claimed last month he had "agreed terms" with the Sports Direct magnate.
Jose Mourinho, Chris Hughton, Mikel Arteta, Garry Monk and Sean Dyche have emerged as the early favourites to succeed Benitez, with Michael Appleton, Slavisa Jokanovic and Gennaro Gattuso also high on the bookmakers' list.