In the space of a week, a story that started out as a report on predatory behaviour by some Oxfam staff in Haiti has transmuted into a crisis of trust, an attack on aid, and a threat to humanitarian action. Penny Mordaunt, the secretary of state for international development, has demanded moral leadership – and rightly so. But how do we now move to constructive solutions?

That question matters for some of the world’s most disadvantaged people. Agencies like Save the Children are a link in the chain between UK public money and the women and children whose lives have been torn apart by humanitarian emergencies. UK aid and public donations mean that we can provide life-saving maternal and child health services for Rohingya refugees in Bangladesh. They enable us to deliver education to Syrian refugees, immunisation to children in the Democratic Republic of the Congo, and protection to unaccompanied children in South Sudan.

Quick Guide How dependent are UK NGOs on the government? Show How dependent are UK NGOs on the government? Last year the UK government dedicated £13.3bn to international aid, with a significant chunk spent through UK charities. But these millions of pounds of aid money are now at stake, following reports of sexual exploitation by Oxfam staff in Haiti. The government has threatened to cut funding to Oxfam unless the charity shows “moral leadership”. In 2016-17, Oxfam’s total income was £408.6m, according to its annual report, which includes £31.7m from the UK Department for International Development (DfID). In addition to money from governments, international organisations and foundations, Oxfam generated £90m last year through its shop and trading network. Around £1.2bn of UK aid is spent annually through NGOs. In 2016, Save the Children secured multi-year contracts worth £91m with the UK government. It describes itself as one of DfID’s “key civil society partners”, which implements around 60 UK government-funded projects in countries such as South Sudan, Somalia and Yemen. In the same year, the British Red Cross received £16.3m in DfID funding. Around one fifth of Christian Aid’s income came from the department, which provided £20.1m in the year 2016-17. Christian Aid reported in its 2016-17 annual report that donations had dropped 13%, which it said was due to “fewer high-profile humanitarian crises”. Some have voiced concerns that as NGOs have become more reliant on government funding, they have also become less willing to criticise its policies. Charities are also nervous that the UK’s aid budget, even before the Haiti sexual misconduct scandal, has been under increasing scrutiny. Last year, the UK was one of only six countries to spend 0.7% of gross national income on aid, a target set by the UN decades ago. Penny Mordaunt, secretary of state for international development, has said the UK remains committed to this target, despite some conservative MPs calling for it to be dropped. In a recent interview with the Telegraph, she said Britain will cut foreign aid spending to wealthier developing countries if they fail to “take responsibility”.

Above all, aid channelled through non-government organisations has the potential to deliver hope in some of the most dangerous places on earth. Three weeks ago, four Save the Children colleagues in Jalalabad, Afghanistan were killed by militant groups for bringing education to young girls in a country with some of the world’s worst indicators for schooling.

Could we do aid better? Absolutely. Does the aid we provide make a difference? I would challenge anyone to visit our nutrition programmes in famine-affected areas of Somalia or Ethiopia and reach a negative assessment.

But trust is at the heart of our contract with the UK public and the taxpayers who foot the bill for the Department for International Development (DfID). This trust is failing – and we have no hope of rebuilding it without tackling the issue at the heart of the current crisis.

An epidemic has affected institutions across our society, from political parties and the House of Commons, to broadcasters, football teams and private companies – and it is global in reach. This epidemic is rooted in the unequal power relationships that enable powerful and predatory men to exploit women and children through bullying, sexual harassment and outright violence. The only antidote is a culture of zero tolerance, backed by rules, recruitment practices, and leadership.

Development agencies cannot get this wrong. We are dealing with some of the world’s most vulnerable people. Across our programmes, we come into contact with women and children who have lost everything. Our staff in Bangladesh are working with Rohingya refugees who have been impoverished, displaced, and traumatised by horrific acts of violence. They have a right to expect and demand the highest standards of protection.

Every non-government organisation must get its house in order. In Save the Children, we have been working to strengthen our screening systems to keep predators and bullies out of the organisation. We have a mandatory code of conduct, have established transparent and accessible whistle-blowing systems, and run extensive and mandatory child protection training. Our child safeguarding teams also bring together staff from across the globe to ensure our programmes meet the right standards.

Yet the truth is that none of us can solve this issue alone. We are faced with a collective challenge. How do we stop humanitarian aid workers who violate our values moving from one organisation to another? How, in an environment when threats to children are globalised but regulatory systems are still national, can we recruit in an international market? How can we as a sector act to swiftly investigate violations of our codes of conduct, support victims, and report with transparency and accountability?

There is no magic solution – but far more could be done. To take one example, an international registry of humanitarian workers backed by a “passport system” would enable us to prevent individuals exploiting recruitment loopholes. Moreover, changes in UK legislation to establish the humanitarian sector as a regulated employment sphere, subject to the same background checks as would apply in teaching or social work in the UK, would help strengthen screening arrangements. And Interpol should be doing far more to identify and report on individuals seeking to exploit humanitarian operations for trafficking, sexual exploitation and child abuse.

The UK’s large international development agencies could also come together to create a global centre on child safeguarding and sexual exploitation, working in cooperation with DfID and national authorities to prevent problems and support victims.

There is no alternative to action. The toxic effects of poor practice in any one of our agencies can weaken the entire sector. That’s why we need to work together to stamp out abuse in all its forms and make sure the perpetrators are held to account.