A boardroom row between Mitchells and Butlers (M&B) and majority shareholder Piedmont has continued after the pub group was urged to produce a new plan of action "within 60 days".

The investment vehicle headed by Joe Lewis has also rejected an offer proposed by M&B, which would see the pub group pledge its support for the appointment of two of the four directors put forward for election by Piedmont. Piedmont said that it viewed M&B's offer of compromise as an "entirely unrealistic proposal", designed to secure the reappointment of Simon Laffin, who would revert to senior independent director with John Lovering as chair.

Piedmont has accused Laffin of being behind "a relentless, baseless, yet highly damaging, campaign" against it, while M&B has suggested that the investment vehicle was looking to take control of the firm in tandem with other shareholders. In an open letter to shareholders, Piedmont said: "Piedmont is open to compromise. We welcome a solution that serves the company's best interests, and we continue to engage with other shareholders to this end.

"It is clear that the principal purpose of the compromise proposed by Mitchells and Butlers is to commit Piedmont to voting in favour of Simon Laffin and two other board members, ahead of the AGM, and to restrict Piedmont's free exercise of its shareholder rights in the future." Earlier this month, the Takeover Panel recently rejected M&B's complaint over Piedmont's activity as majority shareholder before 15 October 2009, although the pub group has asked the panel to continue its investigation to examine activity since that date.