Ken McGeoch last night agreed to stand down as a director of St Mirren after the board demanded that he resign within 48 hours.

The ultimatum was made after it was revealed that McGeoch allowed Gary Withey, the Rangers club secretary, to study "commercially sensitive documents" during his attempt to buy the Paisley side.

That offer was rejected last week, and St Mirren's board made their demand that he resign yesterday following the revelation that Withey attended a meeting in the boardroom last November alongside McGeoch and Paul Davies. The latter pair were seeking the advice of Collyer Bristow, the London law firm that Withey works for, although McGeoch claims that they stopped using the company last February. He also accused the board of mounting a "sustained campaign" to "discredit" him.

"As a lifelong St Mirren fan and board member for 14 years, I have been very disappointed by the [efforts] to remove me from the board," McGeoch said. "The main objective has always been to secure the future of St Mirren. However, the current board believe that the club should be taken in a different direction. Under the circumstances, I would be prepared to walk away. I can confirm that [my] shares are now available for the board and [Richard] Atkinson [a rival bidder] to purchase."

McGeoch also insisted that there was no connection with Rangers "other than sharing the same legal representative".

He also claimed that he sought the approval of the St Mirren directors to include Withey in the meeting, which was a prelude to appointing Collyer Bristow to carry out due diligence.

"Throughout our negotiations, all business has been conducted with full transparency to all current directors of the club," McGeoch added.

Yet the St Mirren board claim they only discovered Withey's involvement last January. Once the details of the meeting emerged - at one stage Withey asked about St Mirren's use of Employee Benefits Trusts, the tax scheme that drew Rangers into a dispute with Her Majesty's Revenue and Customs - McGeoch was asked to resign.

"As a director, Mr McGeoch had every right to inspect [the] documents," the club statement said. "The board, however, consider that his decision to show these documents to an office holder of another SPL club is a serious breach of trust and an error of judgement."

There are no rules to prevent a club secretary acting for another team, although Withey is now only Rangers secretary in name since the club is run by the administrators.