The boardroom bust-up at Hermes, the high-profile activist investor, was triggered when two leading directors pushed for part-ownership of its flagship Focus funds division.

Peter Butler and Steve Brown, the founder directors of Hermes Focus Asset Management, a wholly-owned subsidiary of Hermes Pensions Management, wanted a slice of the business, according to people close to the dispute. But they resigned following a crisis board meeting on Tuesday after the parent company - the £44bn investment vehicle for the BT Group and Post Office pension funds - rejected their proposition. The precise percentage of their ownership wishes remains unclear.