The Make Poverty History campaign group has been banned from advertising on television and radio in the UK.
Media watchdog Ofcom has ruled MPH is a body with political objectives and its TV commercials cannot be shown under laws banning political advertising.
The coalition of more than 500 charities, trade unions and campaigning groups in the UK says it is "disappointed" with Ofcom's decision, insisting its campaign is "the great moral issue of our time" and not "a narrow party-political issue".
Its advertising message includes an array of celebrities, such as movie stars Brad Pitt and Cameron Diaz, clicking their fingers to ram home the message that a child dies of preventable poverty every three seconds.
Says Adrian Lovett, an MPH coordinator: "We will look carefully at the implications of this decision for our future activity."
MPH was created last year with the single goal of persuading the governments of the Group of Eight industrialised countries to write off billions of dollars in debt owed by the world's poorest countries.
UK Prime Minister Tony Blair and his finance minister Gordon Brown have both praised the organisation as having been the deciding factor in convincing the G8 in June this year to agree to write off more than $40 billion (€32.55bn; £21.93bn) worth of debts.
Data sourced from MediaGuardian.co.uk; additional content by WARC staff