Reality Check: Does EU membership attract £1tn to the UK?
In his speech today, George Osborne said: "We have received over £1 trillion of overseas investment into Britain, much of it driven by the fact we are in the EU and its Single Market."
There are two things to consider in this statement.
The first is easy to check - in 2014 an estimated £1.034 trillion was invested in the UK, according to the Office for National Statistics. Normally this involves a foreign company investing in a business or assets in the UK. Only the United States and China had more.
That figure is the total amount of overseas money invested in the UK, not the amount invested in one year. It is the most recent figure available.
But is 'much of that investment driven by the fact the UK is in the EU'? Or is the UK an appealing place to invest in its own right?
The figures show just under half (48%) of total foreign direct investment in the UK in 2014 was from other EU countries. It is hard to say whether this would be the case were the UK outside the single market. However the common rules in the single market make it simpler for firms to expand across the EU, encouraging investment.
The UK also gets more foreign investment from outside the EU than any other member state. Many foreign companies use the UK as a launching point into the rest of the single market.
The UK car industry - the country's biggest exporter to the EU - has seen £1 billion of foreign investment since June 2013.
Financial services, which account for 45% of the overseas investment in the UK, benefits from EU rules which allow the London-based branches of banks from all over the world to do business anywhere in the single market.
The Centre for Economic Performance at the London School of Economics calculated leaving the European Union would cause overseas investment in the UK to fall by around a fifth, even if a Norway-style deal with the EU is secured.
The UK is the fifth-largest economy in the world. It has strong rule of law, a highly-educated workforce and a flexible labour market, making it an attractive investment opportunity in its own right. Analysis, cited by the Treasury, found culture and language, and the UK's tech infrastructure drove investment as well as access to the European Union - though they were all considered important.
Whether "much of" the investment in the UK was because of its relationship with Europe or despite it is impossible to say for sure. However, it is clear the UK's role in the EU adds to its appeal as a place to invest.
Reality check verdict: Over £1 trillion of foreign investment has been made in the UK. Its place in the single market is certainly a factor, but hard to definitively quantify.
READ MORE: The facts behind claims in the EU debate