Everyday 80 million children worldwide do not go to school. Every one of them should have the right to a free education, and when I say that I am thinking of hundreds of young people desperate for the chance of schooling that I have seen with my own eyes.

A few months ago, at Abuja in Nigeria, I met children sitting three to a desk in crowded classrooms, lucky if they had an exercise book or pens to themselves and heard of dozens more children turned away at the door because there was no more room.

A few miles up the road, I was told, an Islamic madrassa was offering education free of charge — in far better classrooms, and to anyone who wanted it.

But the price of education in that madrassa, and in others like it, was indoctrination — by al-Qaeda-inspired militants who subvert the faith taught peacefully in the great majority of Islamic schools around the world.

In Africa, from Nigeria to Somalia, the rise of radical Islamic groups is a large and growing strategic concern for Britain and our international partners.

We know that — despite the obvious focus on the Middle East and Asia — there are probably now more al-Qaeda-inspired cells in Africa than in any other continent — ready to commit their resources not just to terrorism but to the battle for the hearts and minds of young African children who want nothing more than a school to attend.

That is why our “Education for All” campaign is inspired both by a sense of justice and humanity and by a desire for lasting peace and security. For the first time, we propose to do for education what the Red Cross and Médecins Sans Frontiãres already do for healthcare — provide education even in fragile states and war zones.

The UK will begin work with Unicef, Save the Children and other charities to help to finance the mobilisation of the first global roster of education experts and other skilled personnel ever to deliver education in regions of conflict.

And by investing in education for all, we can make a reality of our goal that by 2015 every child in the world should be able to go to school.

It will have to be education free of charge. Because we know that when Kenya made education free of charge one million children appeared from nowhere to enrol for school — and it was only when, in Tanzania and Uganda, aid and debt relief made universal free education affordable that the schools numbers doubled.

Free education for all is not an impossible dream. The average cost of educating a child in Africa is $100 a year, only $2 a week. To educate all 80 million children who do not currently go to school would cost just $10 billion a year — that is 2p per day for every person in the richest nations.

No other investment could be so cost-effective. And as children enrol, ambitions like the plans of Nicholas Negroponte — now backed by six big international companies — to provide cheap laptops for children in the poorest countries, can be implemented, giving them the chance to learn about and communicate with the world in ways we take for granted. More than that: education is the essential foundation on which all further progress depends.

Education is essential to the economic development of the poorest countries — the key to an inclusive globalisation; and the route by which billions of the world’s citizens can rise above a subsistence wage, becoming consumers and contributors to local and national economies.

A few centuries ago the issue was what we could do to Africa, then last century it was what we could do for Africa. This century the issue is what Africa can be empowered to do for itself.

At Gleneagles today, Kofi Annan, Hilary Benn, Jack McConnell and I will meet faith groups and charities to reflect on the 20 months since the commitments made there in 2005 by Tony Blair and other G8 leaders: months of progress in some areas, and disappointment in others.

Debt relief has been delivered to 22 countries and potentially up to £170 billion of debt relief is available. But we still have more to do — most immediately for Liberia, and then for dozens more countries to whom Britain will unilaterally offer debt relief.

Since 2005 Britain too has maintained its pledges to increase aid for health and education, and at Gleneagles today we will call on other countries not to relax their efforts or to retreat from their pledges, but to honour their promises too.

And while the G8 acknowledged the injustice of the current system of world trade, its inequalities still continue. So in the next few weeks we must move the resumed world trade talks forward and put in place the resources for infrastructure that will enable the poorest countries to benefit from trade.

We must deliver urgently on the 2005 Gleneagles commitments because they are both the right thing to do and because it is a new geopolitical imperative that across security, trade, environment, health and education we recognise our essential interdependence.

If we succeed in our education goals, it will be said of our generation that we were the first in history to ensure schooling for every child. If we do not, then years from now, people will rightly look back at us and ask why we commemorated the end of the slave trade in the 19th century and yet tolerated forced child labour and illiteracy in the 21st century.

The Make Poverty History movement in 2005 taught us anew what the antislavery movement taught us 200 years ago: that the great movements for change do not happen by accident or chance. They are founded not on the shifting sands of self-interest but on the rock of social justice, and the insistent and irresistible demand for that justice.

In 1807 a combination of social compassion and moral outrage ended the British involvement in the slave trade. Today that same compassion and outrage must inspire us to tackle the great wrongs of our time and to give every child in the world a better chance — freed from poverty and liberated by education.

Times Recommends

• Caesar & Cicero: Balls & Mandelson
• The anti-sex brigade are the worst
• Small act of charity won’t change the world