Huw Merriman is MP for Bexhill and Battle.

In a recent response to a suggestion that the UK’s aid budget should be diverted to domestic spending because “charity begins at home”, the Prime Minister reminded us that “the record this Government has of ensuring 0.7 per cent per cent of our GDP is spent on overseas aid is a record second to none”.

I am delighted that she has reasserted this commitment ahead of the general election, and now is the time for Conservatives to go to the electorate proud of a manifesto promise that ensures that our responsibilities transcend our borders. Saving lives across the world is a cause for celebration, not embarrassment.

Although it may not always feel like it, the world is changing for the better. Support from the UK and other developed nations is helping to achieve a level of prosperity not seen before. Since 1990, extreme poverty has halved; then, 12 million children a year were dying before their fifth birthday, now, it’s 5.9 million. Progress is possible, but investment is vital.

Unfortunately, the transformational impact of British aid has recently been overshadowed by allegations about the quality of the projects the Department for International Development (DFID) funds and the integrity of its partners. These claims should be investigated, and poor practice exposed. There should be ring-fencing of the principle that any public department involved in spending taxpayers’ money is held to the highest standards.

But this issue must not be conflated with the overall effectiveness of aid. The overwhelming evidence is that UK aid is saving lives, expanding opportunity, and creating jobs. Consider the case of childhood vaccination, an area that DFID invests in heavily through a unique public-private partnership which pools investment from international partners and the private sector to develop and distribute vaccines.

Since its establishment in 2000, this programme has reached 500 million children and prevented more than seven million deaths in the process. The Johns Hopkins Bloomberg School of Public Health recently examined the economic impact of these results. When looking at both the direct and indirect impact of illness – including treatment and lost productivity – they found that the return on investment was £44 for every £1 spent.

In considering the spectacular results which our UK aid budget can deliver, it is critical that value for money underpins spending decisions. Every pound wasted could be a life wasted. However, delivering aid is not always easy. When responding in some of the most dangerous places in the world, or trying to help the world’s most desperate people, things will not always go according to plan.

Evidence tells us that voters are proud of the results which UK aid delivers. British people are sceptical and suspicious about the way that aid is spent – but not about the fact that Britain should spend aid. Recent analysis of centre-right voters’ perceptions of aid found that they support aid because they are proud of the difference that this country makes for the world’s poorest people. ConservativeHome readers also justify aid spending because it is “good in itself” not because it is “good for us”.

To help those less fortunate than ourselves is a basic human instinct, and one that we should celebrate. I felt this personally when visiting the Syrian border last year. Spending time in the world’s second largest refugee camp, I saw UK aid delivering food directly to 80,000 camp residents who had temporary shelter with clean water supplies. There was none of the obvious squalor that exists in the camps in France. The aid programme isn’t just spent on food and shelter, but on education and empowerment. The Syrian migrants I spoke to did not want to come to Europe, but their views would change if they did not have the support and opportunities which our budget is delivering.

Witnessing the transformational effect of the UK’s aid programmes gave me an enormous sense of pride. Our generous support is offering these refugees a future and a chance to stay close to home. The world is on the march. Reduce the overseas aid budget, and we will be spending it on increasing our border control. It is a lesson our European partners are all too aware of.

In upholding our commitment to this budget, the Prime Minister spoke for many when she said that “we should all be proud of the help and support we are giving to people around the world who are living in incredibly different circumstances. We look after old people here in the UK, we also take that moral responsibility for people around the world seriously as well.” And as the UK leads the world in responding to the devastating food security crisis unfolding in East Africa, never has this sentiment been more important.

All of us who support aid must not be afraid to proclaim it. When poor practice is unearthed, we must demand improvement, but we must not retreat from our position that helping the world’s poorest is the right thing to do. The case for aid is sound, we must now get better at making it, and it must be at the core of the message we take to the country on 8th June.