Staff at Save the Children are bracing themselves for redundancies after the charity announced it is to devolve decision making to developing countries.
The aid agency said it wants to decentralise support functions, which could include recruitment, finance and IT, from its headquarters to country and regional offices.
Chief operating officer Peter Harlock described the process as a reshaping of the entire organisation, aimed at "taking decision making closer to our work on the ground" and keeping overheads as lean as possible.
The charity employs 400 staff at its London head office. A further 150 are employed abroad on UK contracts. All staff have been told that posts will go, but they will have to wait until next month to find out which ones.
Trade union Amicus, which represents staff at the charity, said the changes were driven by a financial crisis caused by falling income and dwindling reserves.
"I believe it is really about the bottom line and needing to make massive savings," said Amicus regional officer Sarah Cook. Save the Children denied this.