The Disasters Emergency Committee, which represents 14 of Britain's aid agencies, has until the end of June to find new central London premises, after the charity's troubled landlord Consignia refused to renew its lease.
Consignia had been charging a peppercorn rent of £1 a year but last week - when it axed 15,000 jobs - said it no could longer afford to subsidise the organisation.
Brendan Gormley, chief executive of the Committee, has sent out a plea to his corporate contacts, such as the broadcasters and banks that help it during major appeals, to offer a similar deal.
Gormley is talking to the organisation's members, which include Oxfam, Christian Aid and Save the Children, about increasing their donations, to enable it to pay for a 1,200 to 1,500sq ft office at a maximum of £25 per sq ft.
The Committee employs five full-time staff but can triple in size during appeals when staff, such as press officers, are seconded from its members.
It has raised £155 million in recent years in response to events such as the Kosovo war. "Another crisis could occur at any time,