Who - if anyone - could replace Martin Sorrell?

There’s something almost Shakespearean about the WPP board calling in legal counsel to investigate allegations of personal misconduct. Sorrell has denied any wrongdoing but the question of his remained tenure at the company has never looked more in doubt.

Some analysts have predicted that he won’t be replaced – instead the board will break up the company into its component parts and sold off in order to maximise its value. But there remain a number of people likely to have an eye on the job.

Mark Read

The frontrunner is Mark Read, the global chief of Wunderman, who, as the former head of digital at WPP, is a familiar face to investors. He is also credited with having done a good job in turning around the fortunes of the formerly rather dusty Wunderman network.

Karen Blackett

Other names in the frame could include Karen Blackett, who was named WPP’s first UK country manager. Ambitious and hardworking, promoting a woman – and a black woman at that – to the role would be a powerful statement. However her lack of experience in dealing with the City might stand against her.

Lindsay Pattison

Similarly Lindsay Pattison – another of Sorrell’s key lieutenants – would be an interesting choice. As WPP’s chief transformation officer she has been tasked with Sorrell’s strategy of driving "horizontality" (cross-selling agencies) – the success of which might be in question.

Johnny Hornby

Johnny Hornby, the chief executive of The & Partnership, has never been shy of letting his ambition be known. He puts himself forward as a regular media pundit on advertising-related issues and in The & Partnership he has experience of building and managing a network, albeit on a micro level. While Hornby now likes to portray a more statesmanlike image, he has a past reputation for partying hard.

Kelly Clark

Also from the media side of WPP are possible candidates in the form of Kelly Clark (left) and Stephen Allan. Having made his way up the WPP greasy ladder, with regional jobs in Mindshare, then running Maxus globally before working his way up to become global chief executive of Group M, Clark’s loyalty to the company is admirable. The impressive, no-nonsense Allan has also been a loyal lieutenant running the jewel agency in the media agency crown – MediaCom.