Thirteen years ago, the British economy was the 4th largest* in the world. By 2030, our economy will probably be only the tenth largest. By then, our economy will have been overtaken in size by that of Mexico, Brazil, India and Indonesia whilst China and the United States will remain the world's dominant forces. As economic size is inextricably linked to influence, this poses a substantial threat to British influence in the world.
The EU economy, however, will remain firmly in the world's top four largest economies and would be even larger if the long term aim of Turkish accession is achieved. Being part of this economic superpower will give the UK the ideal platform from which to amplify our voice and increase our influence in a world of billion person countries and trillion dollar economies.
There is also the increased danger, that outside of the EU, the UK would become a medium sized economy perched on the fringes of an economic and geopolitical superpower, whose interest could be at times in competition with that of the UK.
From a position inside the EU, the UK has been able to shape the EU's direction of travel and foreign policy objectives. British influence has driven many of the EU's most successful policies, such as the development and implementation of the single market and the progress of EU enlargement.
With France, the UK dominates defence capability and possesses the EU's only permanent seats on the UN Security Council. The UK also has historical links with some of the emerging economies, the Commonwealth and has unique ties with the USA.
Some would see these strengths as arguments that the UK should leave the EU, believing that because of our existing status in the world, our influence will be forever assured. This, however, ignores the ways in which the world is changing around us and the fact that the EU amplifies our influence and serves to strengthen our trading links and power to prise open new markets.
Far from isolationism, the global trend is for regional multilateralism with regional cooperation in South America with Mercosur and in South East Asia with ASEAN in South East Asia. These bodies take inspiration from the successes of the EU.
Rather than retreating from Europe or threatening to leave, the UK must remain a full member at the heart of a progressive and outward-looking EU. By leading the case for sensible reform from the inside, we can ensure that the EU continues to work towards our aims and that our membership remains firmly in the national interest. From this position, our global influence will be strengthened and our voice amplified in a changing and uncertain world.
* This article has been updated.