Mark Goldring, who has led Oxfam since 2013, has come under pressure as the organisation reels from a prostitution and sexual abuse scandal.
However, despite his deputy Penny Lawrence having resigned on Monday, Mr Goldring intends to remain in post during the crisis unless he is told to go by the charity’s board.
On Tuesday, he was offered strong support by Oxfam’s chair of trustees Caroline Thomson.
“We have complete confidence in Mark Goldring, he’s doing a brilliant job and Oxfam’s a wonderful organisation which is going through some difficult times,” she told Sky News.
Ms Thomson described the charity as “very ashamed” by claims senior aid workers used prostitutes in Haiti, amid an international relief effort in 2011.
But she added: “We’re going to move on and, I hope, continue to earn… the support of the British public.”
The Haiti revelations, first reported by The Times newspaper, sparked further claims prostitutes were also used by Oxfam staff in Chad in 2006.
Although the allegations refer to events before his tenure, Mr Goldring has since been directly dragged into the controversy after a whistleblower claimed he failed to act on concerns raised to him in 2014.
Helen Evans, Oxfam’s former global head of safeguarding between 2012 and 2015, claimed she begged the charity’s bosses, ministers and the regulator to act on sexual abuse allegations.
She said that while she was working at Oxfam she was told of three examples of sexual misconduct in the space of 24 hours.
Ms Evans claimed she was told about two women being coerced to have sex and a worker who had failed to say he had previously been struck off for sex abuse.
She also detailed concerns about abuse of staff as young as 14 in Oxfam shops.
In response to her allegations, Mr Goldring apologised for “not acting fast enough” on her concerns, after Ms Evans claimed Oxfam bosses cancelled a meeting with her at the last moment.
He told Channel 4 News: “I think we did take them seriously and we responded on many different fronts – the records checking was one of them, training was another, the promotion of the helpline was another – she did some great work.
“What I recognise now, with the severity of issues as they have emerged, is that we should have resourced that team up faster as we now have, indeed, done.”
Saying he would not resign as he was not in post at the time of the Haiti allegations from 2011, Mr Goldring added: “If our board turn round and say ‘actually you are not the right person to lead us forward’ then I of course would resign immediately.”
Mr Goldring is likely to be among senior Oxfam figures to face a grilling by MPs next week, as the House of Commons’ International Development Committee meets on Tuesday in response to the charity’s ongoing scandal.
Haiti, which suffered a devastating earthquake in 2010, has sent a warning to international aid agencies following the claims against Oxfam.
Hitting out at “a violation of basic human decency”, the Caribbean country’s president Jovenel Moise said in a statement: “Let this be well-understood by all agencies: if your staff exploits or harms our communities while ‘aiding’ them, we will not tolerate your particular brand of support.”
Oxfam’s leaders in Haiti are expected to be called in for crisis talks with Mr Moise’s government.
The charity’s reputation suffered a further blow on Tuesday after Juan Alberto Fuentes, chairman of Oxfam International, was arrested in Guatemala as part of a local corruption investigation.
Mr Goldring met with International Development Secretary Penny Mordaunt on Monday, who has said she is taking the crisis “very seriously” but insisted she will not act “hastily” when deciding whether or not to stop handing Government aid cash to Oxfam.
Oxfam received £31.7m of taxpayers’ cash in 2016/17, with its funding part of the Government’s £13bn per year foreign aid budget.
Former international development secretary Justine Greening has said she does not recall being aware of allegations surrounding Oxfam workers in Haiti.
Speaking to Sky News, the Tory MP said she was “absolutely shocked” to hear the claims and insisted any allegations “would have been followed up”.
Ms Greening spoke out after her successor Priti Patel claimed Oxfam’s prostitution scandal is “only the tip of the iceberg” and warned there has been a “culture of denial” in the aid sector about exploitation and sexual abuse over decades.
An inquiry into the Oxfam sex scandal by the Charity Commission was due to get under way on Tuesday.