Invesco has been attacked by a leading shareholder over an "unjustified" attempt to oust directors at one its investment trusts —an increasingly acrimonious spat that has broader implications for the governance of UK mutual funds.

Invesco filed a resolution calling for the sacking of the independent chairman of the Invesco Perpetual Enhanced Income Trust, and another of its senior directors, on May 22, following a dispute over the fees that the fund pays to Invesco.