Here is an interesting post from elsewhere on the vacuum of politics in most of the NGO sector in the UK. It suggests that part of the reason for this is that they have allowed themselves to be contracted by the state, becoming part of the outsourcing industry.
However this can’t be the whole picture as the absence of resistant political stances in the NGO sector also affects organisations who aren’t involved in contracting. Red Pepper recently had a piece about the poverty of political thinking in NGOs. It is well worth a read.