Proxy adviser CGI Glass Lewis has slammed efforts by powerful Singaporean investor ARA Asset Management for representation on Cromwell's board while also pursuing a partial takeover of the ASX-listed fund manager as "disingenuous".

The intervention from the well-known proxy house comes in the countdown to the third effort by ARA, Cromwell's largest investor, to regain a presence on the board through a vote at a shareholder meeting on September 18.