But who will become their sixth manager in four years? Here PA Sport's Matt Simms looks at some of the contenders.

Gus Poyet

The current number two under Juande Ramos at White Hart Lane is the bookies' favourite, having previously worked with Newcastle's executive director (football) Dennis Wise at Swindon and Leeds. The likeable Poyet has been a hit with the media and fans at previous clubs and is also extremely ambitious, having worked his way up through the leagues in less than three years.

Dennis Wise

Officially Wise's job is to report to the board about footballing matters but he is also thought to be involved in youth development, scouting and transfers. Has coached with some success at Millwall, Swindon and Leeds but the fiery character would be incredibly unpopular, with many fans blaming him for Keegan's exit.

Alan Shearer

Shearer is a god on Tyneside, having played nearly 400 games for his home-town club and scored over 200 goals. Would be the unanimous choice on Tyneside but is reluctant to step into management at such a volatile time with no experience.

David Moyes

Moyes' reign at Everton has been a successful one, highlighted by leading them to qualification for the Champions League in 2006 and a good run in the UEFA Cup last season. He has been linked with Newcastle before and doubts still remain over a new contract at Goodison Park with his current deal set to expire at the end of the season.

Didier Deschamps

The former Monaco coach has been out of work since guiding Juventus back into Serie A after they were relegated in the wake of the match-fixing scandal in Italy. Has experience of the Premier League having played for Chelsea and is used to the continental style of management.

Alan Curbishley

Similar issues to Keegan forced him to quit West Ham earlier this week so it is unlikely he would jump from the frying pan into the fire. However, remains one of the most highly-rated English managers and will only consider top-flight jobs.

Frank Rijkaard

Having left Barcelona at the end of last season, the Dutchman has experience of managing the biggest clubs at the highest level. His teams have a reputation for playing attractive football - apart from the later stages of his reign at the Nou Camp - which would appeal to the Toon Army.