A European Union without Britain would be financially poorer, less economically liberal and free-trading, less Atlanticist and less open to further enlargement.

A British vote to leave the 28-nation EU in a referendum on June 23 will not only deal a severe blow to the union's self-confidence and international standing, amputating it of its second biggest economy and one of its two main military powers.

It would also blow a hole in the EU's common budget and tilt the balance away from the open, competitive economy favored by the Netherlands, Sweden, Ireland and central European states, toward protectionism and heavier regulation.