(Reuters) – Two major shareholder advisory firms urged investors to vote against billionaire investor David Tepper’s hedge fund demand that Allergan Plc immediately split the roles of chief executive officer and chairman, in a boost to the Botox maker.

FILE PHOTO: Allergan ticker info and symbol are displayed on a screen on the floor of the New York Stock Exchange (NYSE) April 6, 2016. REUTERS/Brendan McDermid

The recommendation from Institutional Shareholder Services LP and Glass Lewis & Co against the proposal of Tepper’s Appaloosa gives firepower to Allergan Chairman and CEO Brent Saunders ahead of the drugmaker’s shareholder meeting on May 1.

“Their recommendations affirm our position that our plan to adopt separate Chair and CEO positions with the next leadership transition is the best approach