"There are two key issues to which no-one can find a solution at the present time and, in the absence of a solution, I cannot take the club any further.

"These two issues will cause damage to the club and will hold the club back.

"It is obvious from Gary Megson's comments in the press and from comments he has made to me personally that he wishes to see me step down as chairman and he has now got his wish.

""I think it is pretty clear that Gary would like me out of the job of chairman and there has been a whispering campaign going on for quite a long time."

In an open letter to fans, Thompson outlined the two issues which have caused him to depart.

Integrated approach

"Public comments which Gary makes repeatedly result in almost constant public criticism of the chairman and the board, which is totally unjustified," he said.

"It is never acceptable for a manager to publicly criticise a chairman or the directors any more than it is acceptable for a chairman to publicly criticise a manager.

"We all have a hard enough job to do without public criticism being inflicted by our senior colleagues.

"I have also clearly stated that West Bromwich Albion's scouting system isn't good enough.

"Gary has stated that the scouting system was his dad and a couple of Gary's mates and the lack of a proper scouting system has held the club back for years."

Thompson criticised Megson's plans to control the scouting system, which involve telling the board which players to buy.