Mark Curtis, who recently left Christian Aid after three years, and who previously spent four years as head of advocacy at Action Aid, believes the big five overseas aid NGOs currently have little influence on national policy because of their strategy of engagement with the Government.
"Senior managers of these organisations enjoy hob-nobbing with ministers, believing this gives them influence, when it rarely does," he said. "Talking politely to the Government doesn't often work. I think most supporters of these NGOs would be horrified by the degree to which they are co-opted by the powerful."
Curtis praised some NGOs such as Oxfam and Christian Aid for developing wide supporter and campaigning bases, but felt they should be using that advantage to press for changes in government policy and to build a wider movement for development in the UK.
"They must mobilise these supporters to challenge the Government," he said. "But many NGO directors have become obsessed with increasing income growth and profiles, and have put that above the ability to have real influence."
He said there should be much more direct action by NGOs. "Why are they too polite to engage in non-violent direct action?" he said. "They should be locking themselves and ministers into buildings. But they feel they can't because they are too close to them."
He added that northern hemisphere NGOs should bring more southern NGOs to the UK to confront the Government, and should be part of, rather than shunning, the anti-globalisation movement, which they considered to be too activist.
Tim Moulds, churches director of Christian Aid, said it does have a radical agenda: "It can only be achieved by concerted pressure - combining individual pressure on politicians both by those who vote for them, and by convincing arguments put to them by people whose technical expertise they respect. Agencies have to be able to do both."