Let me take you to northern Uganda on the border with South Sudan, where you will find one million refugees, brought there by war, disease and drought. And to the Bidi Bidi camp in particular, which I visited recently, where over 270,000 refugees now live. Refugee numbers here are growing faster than even in Syria, yet it’s a place largely forgotten by the world.

It hasn’t been forgotten by the UK though. I saw British investment and expertise in aid helping to build temporary shelters and cooking warm meals for families, vaccinating children on arrival and providing sanitary towels to young women. It made me proud to be British.

But more still needs to be done. What I found shocking was how little the amount of food these families were given was. 12 kilos of dried maize and beans to last them 30 days – and even this is reduced after a few months in the camp to half this amount. The Ugandan government has given them land which is admirable but they are unable to grow enough food on their small plots to replace the reduced food rations. So there is an urgent need to provide more food aid and ongoing support.

Sadder still is the emotional plight, and vulnerability, of these refugees. The camp is full of women and children. I met Edison, aged 15. He was wearing a white wristband, to signal he was on his own. And he told me how his parents were attacked and killed outside their home which was then set on fire – and how he left on his own to cross border. He walked for several days in flip flops, dodging snakes and scorpions, without food or water, fleeing violence in Juba and other districts. He will bear the emotional scars of this trauma for years to come. It’s UK aid that is offering him the crucial emotional, as well as physical, support he needs to deal with what he has been through. Working with NGOS like World Vision, we are helping to create places where children can recover and look to rebuild their lives without venturing any further from their homes.

And here, for me, lies the rub. Investing in aid is not just about doing what is morally right, it’s about what is good for the UK too. The refugee crisis in East Africa can’t be ignored and isn’t going to end tomorrow. And we can either wait for things to get worse, and provoke an even bigger refugee crisis around the world. Or we can help people rebuild their lives. No one I spoke to at the camp had wanted to leave South Sudan, when it is safe to do so they want to return home. But in the meantime they just want the opportunity to make their lives better. Put another way, if the UK and other international donors don’t continue to support these refugees they will face starvation and it will increase the likelihood of migration to other countries where they can find basic resources.

I know some people will say: charity begins at home. That’s true, it does – and our responsibilities should start with those who are struggling here in the UK. But charity doesn’t end here. We have a duty to those beyond our shore. It is the morally right thing to do.

I know others may say: aid can’t solve all these problems. And again, I agree. It is not a silver bullet that can solve the world’s problems at a stroke. Free trade, active diplomacy, strong defence – these are also the things that help make the world a better place. But I believe Britain is at its best, and makes the biggest difference, when it leads in development as well as defence and diplomacy.

It’s about making the world a safer place. When Ebola struck West Africa, it was British aid workers like NHS nurse William Pooley who put their lives on the line to help out and stop that disease from spreading. It’s about making the world a healthier place. Every year, thanks to British aid, 67 million more children have been immunised against preventable diseases. Just think about that. And aid helps make us all better off too. It’s aid that let’s people in poorer countries get the skills and resources they need to stand on their own two feet – spreading economic opportunity, producing our trading partners of the future and creating the conditions where future aid spending is no longer needed.

Of course, aid is not perfect. I’m the first to criticise corruption and mismanagement. But the Government has already taken significant steps to ensure that our taxpayer money reaches the most vulnerable and also provides value for money. And as I saw at Bidi Bidi, when it works, when it is targeted, when it is making a real difference, it really does show Britain at its best. A Britain that is leading.