Ben Summerskill, the chief executive of gay charity Stonewall, has become the fourth commissioner to resign from the Equality and Human Rights Commission in the last week.

Those who have already resigned have attacked the leadership of chairman Trevor Phillips, while the National Audit Office refused to fully sign off its accounts, citing concern over consultancy fees paid to four members of the Commission for Racial Equality who had already received large redundancy pay-offs.

Summerskill is the first commissioner to call for Phillips’ resignation.

He told PinkNews.co.uk: “There have been further headlines this morning about the leadership of the commission. I think its time for him [Phillips] to step aside and make room for someone who can deliver outcomes.

Confirming he had emailed his resignation to deputy leader of the Labour Party and equality minister Harriet Harman at around 1pm, he added: “I’m sad because I do feel that a commission that encompasses all is hugely important. We at Stonewall will give it all the support it needs.

“I hope the commission will think about how it is organised so it can deliver the outcomes it needs to. There are still millions whose lives are disfigured by prejudice.”

Three commissioners have resigned from the quango since last Friday, reportedly over the way the organisation is being run. Another two resigned earlier this year.

Those who have resigned in the last two weeks are Sir Bert Massie, former chairman of the Disability Rights Commission, Baroness Campbell, the disabilities rights campaigner, and Professor Francesca Klug.

In a resignation letter to equalities minister Harriet Harman, Mr Massie said: “I have been concerned for some time about corporate governance at the Equality and Human Rights Commission and had hoped that renewed leadership would enable it to achieve its full potential.

“The reappointment of the chairman has dashed that hope and as I cannot agree with the way in which the commission is led. I must, with regret and sadness, offer my resignation with immediate effect.”

Professor Klug cited the “problems of leadership and governance we have experienced at the commission”.

She added: “There is a wealth of experience and good judgment on the board and I regret that we have not always been able to use this collective strength to best effect.”

An EHRC spokeswoman said Summerskill would remain a commissioner until December, when his term ends.

She added: “It is regrettable that Ben Summerskill has chosen not to reapply for a position as Commissioner, given his experience and expertise. But we need to focus on what we’re delivering for the public. That is what they are interested in.

“The commission, led by Trevor Phillips, continues to work on a number of substantial fronts including delivering a new Equality Bill which will make Britain a fairer and better place to live and making our Human Rights Inquiry recommendations lead to real change in public service delivery.

“We will also be completing our formal inquiries into gender pay and the finance sector and race and the construction industry and announcing a new grants programme, supporting grass-roots organisations who are making a real difference. These are the things that matter, showing a clear sense of direction with our three-year strategy which was unanimously agreed by the board.”