9 March was a special day for the UK and international development, and one that has taken nearly half a century to arrive. A bill to enshrine in law the promise to give 0.7% of the UK’s annual national income to overseas aid has cleared its final Parliamentary hurdle. This commitment is the result of a remarkable level of cross-party support and cooperation, which is to the credit of many MPs and Peers past and present, including Michael Moore MP, whose Private Member’s Bill, following Royal Assent, will now become law. We thank all of these Parliamentarians for their unwavering support. It is also a key milestone for UK aid, which every year helps to save and improve the lives of millions of people around the world. A disabled grandmother from Zambia, Esther Cheelo (centre) often went a month at a time without bathing or ate only one meal a day because she could not manage the 5km walk to the nearest water supply. Now that WaterAid has fitted a borehole in her village Esther says her life has been “completely transformed. Photo: WaterAid/ Chileshe Chanda Despite some major successes in tackling extreme poverty during the Millennium Development Goals period, the 0.7% target is as necessary as when it was first set in 1970. Today, more than one billion people live in extreme poverty, 870 million are hungry, 2.5 billion have no access to adequate sanitation, 60 million children between six and 11 are not in education, and around one in ten people do not have safe water to drink. Compounding the difficulty in addressing these and other development challenges are the economic activities of wealthy countries, which scientific evidence shows are pushing vital global ecosystem functions past dangerous thresholds. Interlinked crises of climate change, environmental pollution, acidification of oceans, loss of biodiversity, and depletion of key natural resources are exacerbating development issues, with poor countries and poor communities most affected and at-risk. This is a fundamental injustice, given their vulnerability and minimal responsibility for such changes. The Sustainable Development Goals, which UN member countries are expected to adopt in September this year, seek to address and improve these development and environmental issues by 2030. Implementation of these goals will require substantial funds, with overseas aid forming a crucial part, particularly in the poorest countries and most fragile states. There has never been a more important time for wealthy countries like the UK to play their part in international aid. In recent years, the UK has helped 43 million people to access safe water, better sanitation or improved hygiene conditions, and helped more than ten million children – half of them girls – to go to primary and lower secondary school. It has had a key role in fighting Ebola in West Africa and providing humanitarian assistance in Syria. These are just some of the key reasons why UK aid is a vital source of financing the tackling of poverty around the world. Legislating to meet the 0.7% target makes a durable commitment for the years ahead, and reinforces the UK’s place as a world leader in international development. Whatever the result of our General Election in May, it is vital that the new Parliament continues to champion the UK’s leading role in ending global poverty and achieving sustainable development. John Garrett is WaterAid’s Senior Policy Analyst – Development Finance. He tweets as @johngarre and you can read more of his work here > For global policy, practice and advocacy updates and discussion, follow @wateraid on Twitter.