Eleven international NGOs from leading human rights, environmental and social development groups have drawn up the world's first accountability charter for the not-for-profit sector.
The voluntary charter sets new standards of openness and ethical behaviour in campaigning, fundraising and reporting, and makes reference to universal human rights principles and responsible advocacy.
The founding signatories, which include Oxfam, Amnesty, Survival International and ActionAid, agreed to the ground-breaking code of conduct at a conference in London last week.
NGOs have come under mounting pressure to observe the same standards of conduct that they demand from their campaign targets, many of which are multinationals or governments.
Irene Khan, secretary general of Amnesty International, said: "NGOs are playing an increasingly prominent role in setting the agenda in today's globalised world. This places a responsibility on us to act with transparency and accountability.
"The charter shows that NGOs are willing to adhere to a code of conduct and encourage others to follow."
The signatories are inviting all international NGOs to join the charter.