A top private equity lobbyist rebuked Donald Trump for missing chances to alter his tone for the general election, saying the Republican presidential candidate could cost supporters of the industry congressional seats and influence.

Mike Sommers, president and chief executive of the trade group American Investment Council, said Trump "wasted" opportunities to shift his message, and "reinforced the American people's view that he is temperamentally unfit to be president". He spoke during Private Equity International's Investor Relations and Communications Forum in New York on June 14.