The Charity Commission has issued a plea to minority groups to join a new feedback forum after none responded to its initial invitation.
The commission announced six weeks ago that it wanted to recruit 150 voluntary sector individuals to form a customer service network, which will provide feedback on the regulator's performance.
So far only 40 people have responded - and none from gay, lesbian, Jewish and black and minority ethnic groups.
"We're concerned to ensure that the network includes a good cross section of the voluntary sector," said a commission spokeswoman.
The commission is trying to cultivate a more inclusive, touchy-feely style of leadership under new chair Geraldine Peacock.
She was urged to show "greater humility" than her predecessor when grilled by the parliamentary committee scrutinising the draft Charities Bill in July.