An increasingly acrimonious period of infighting at FC United of Manchester – the breakaway club set up after the Glazer family’s takeover of Manchester United – led to another resignation on Monday after one of the board members announced he would be standing down because of what he described as “an orchestrated campaign” against the regime.

Adam Brown’s resignation, citing a “hate campaign” and “personal attacks”, follows the decision of Andy Walsh, the general manager, to stand down amid criticisms from parts of the fanbase that the club have abandoned their founding principles and with a potentially volatile general meeting scheduled for Sunday, when he was facing a vote of no confidence.

The Guardian reported on 31 March how the club’s famed togetherness, leading to the move to their £6.3m Broadhurst Park stadium this season and the team’s rise to the National League North, the sixth tier of the football pyramid, had been threatened by a series of divisions that had led to legal action, resignations, protests and gagging orders.

Brown, a close ally of Walsh, has been one of the driving forces behind the club since it was formed in 2005. Both men have been instrumental in FC’s success over the last 11 years but their regime has increasingly come under fierce criticism in recent weeks.

“An orchestrated campaign against the board, the staff, the club collectively and some of us individually, has made life very difficult,” Brown said in a statement. “While in a democratic club debate and disagreement is part and parcel of what we are, that debate must be conducted in an atmosphere of respect. Debate has increasingly been conducted in a fashion that is not acceptable including unjustified personalised attacks on some staff, volunteers and individual board members.”