Something really momentous happened last week. Something that the whole world should be celebrating. We found out that there had been the biggest fall in history in the numbers of children dying from easily preventable diseases or from simply not having enough decent food to eat. Put simply, there are millions more kids alive today thanks to the success of international aid.

This is the reason why the Prime Minister deserves huge credit for being unequivocal in promising to stick to his commitments to help poorer countries. But just when we are making this dramatic progress and there is the chance to be the generation that ensures no child dies from diarrhoea, pneumonia, malaria or hunger, and that every child has the chance to go to school - aid has come under unprecedented attack.

Recent newspaper coverage would suggest that British aid is being frittered away; squandered on undeserving countries and wasted. It is right that tough questions should be asked about how Britain gets value for its money, and it is spent in ways which help the poorest most.

However, we cannot let all the progress that has been made and the potential that could be achieved be drowned out by claims that aid is ineffective, unnecessary or wasted. Because the bigger picture is that aid works. Aid that costs just a penny in every pound.

In the past decade more than 50million children have been able to go to school as a result of debt cancellation and increased aid. Most recently Britain helped to feed 3.5million people caught up in the East Africa Food Crisis. And our aid will vaccinate one child every two seconds, immunising 80million children in all, saving 1.4million lives over the next five years. This is the hidden story of success - that British aid transforms the lives of millions of the world's poorest people.

My visit to one of the refugee camps in Syria recently bought home how vital British aid is. The children I met told me about their horrific experiences, some who were tortured, others who had seen their loved ones shot and killed. All had had to flee Syria leaving everything behind. But they were safe, had been give the basic essentials and were receiving help to overcome what they had seen. All thanks to British aid.

Aid is not only morally right but it is in our interests too. By supporting developing economies such as China we create opportunities to trade, helping create jobs here in the UK. UK aid also helps protect our security - preventing fragile states becoming havens for terrorists. Giving aid to poorer countries helps creates jobs within them helping end poverty so that people can afford to feed their families and no longer need be dependent on aid.

Giving aid is part of our DNA. For 82 years the vast majority of British people have supported the UK's policy to help those countries in greater need and felt it the right thing to do. It has helped make the UK the global leader that we are today.

A recent poll found that 55% of British people think we should keep our promises to increase the level of overseas aid, a commitment mirrored by the coalition government. Just 27% say we should cut it.

It is tough at home, but we cannot balance the books on the backs of the world's poorest, ignoring the needs of those in greater need than ourselves. As the Prime Minister said: "To those who say we can't afford to act: I say we can't afford to wait."