The man at the centre of the row is Peter Lynch, the executive chairman of Prime Active Capital (PAC), an Irish investment house that owns 21% of Media Square.

On its website PAC says it “targets and acquires companies where value can be achieved through improving and reinvigorating management teams, debt/equity re-structuring, market re-positioning and cash flow enhancement”.

PAC bought shares in Media Square between October 2007 and May 2008 and in July this year Lynch was set to meet the firm’s directors to discuss his “demand” for a seat on the board. According to letters sent to Lynch by Media Square’s board, copies of which were sent out to shareholders ahead of the AGM, he cancelled the meeting and did not respond to written questions about his intentions.

In another letter Media Square said: “For more than 12 months we have been writing to you asking to be clear about what you are trying to achieve,” and “if you or any associate wish to take control of this company, you should make an offer to all shareholders to buy the company in the normal way”.

“We are not prepared,” Media Square wrote, “to allow you to try and obtain influence and creeping control through trying to force us to accept you as a director on the board.”

Media Square said that Lynch “has not demonstrated any clear understanding of how MSQ and its component agencies operate, has offered no practical suggestions for ways to change our strategy or operations, apart from general comments made about a return to an acquisitive strategy, nor has [he] offered any assistance in finding clients or recruiting talented staff”.

Managers from Media Square’s agencies around the world have signed a letter backing the attempt to block Lynch’s appointment – including Illuminas CEO John Connaughton.

Lynch did not return calls to comment.