Action Aid has accused the UN Secretary-General Kofi Annan of hypocrisy after he barred NGOs from next year's UN Millennium Summit on global poverty.
Annan has said that lack of space in the UN building in New York and security concerns mean that civil society organisations will not be allowed to join world leaders at the talks next September.
The summit will review progress towards reaching the UN's anti-poverty Millennium Goals, five years after their launch in 2000.
Action Aid claims it is senseless to ban NGOs when the UN has designated them key partners. At present, the charity says progress is so slow that the UN will need a further 100 years beyond the current 2015 deadline to achieve its targets on reducing child mortality by two-thirds and halving world poverty.
"The declaration at the 2000 Millennium Summit committed the UN to develop strong partnerships with civil society organisations to wipe out poverty," said Steve Tibbett, Action Aid's head of policy and campaigns. "It is hypocrisy for the Secretary-General to exclude us and similar groups from these vital talks. Far from improving security, this decision could make New York less safe, with campaigners left out on the streets as world leaders debate poverty behind closed doors."
The ban on NGOs was made as Oxfam released estimates that 45 million more children will die by 2015 because rich countries are not providing enough resources to fight poverty. Aid budgets are half the level they were in 1960, it said.
"2005 offers the chance of a historic breakthrough but unless world leaders act now, the year will end in shameful failure," said director Barbara Stocking.
A spokesman for Annan's office said that the Secretary-General had called on the UN General Assembly to organise a two-day hearing with NGOs next June as a way for them to influence the summit, but that broader participation was not possible.
A spokeswoman for Action Aid said there was a growing trend for NGOs to be shut out of international governmental and trade summits following the breakdown last year of the Cancun talks on trade liberalisation after African countries refused to sign. "World Trade Organisation officials felt civil society brought down the agreement, and since there has been restricted access," she said.
According to the charity, 30,000 children under five die each day in sub-Saharan Africa, five years after the announcement of the Millennium Goal to cut child mortality in the region by two-thirds. It estimates the target to cut the number of people who die from Aids, TB and malaria will not be reached until 2165.