The paper argues that the familiar pro-enlargement arguments deserve a critical examination. It investigates the impact of enlargement on British business; on the prospects for EU reform; and on the accession states themselves. From each perspective, the study finds that the supposed benefits of enlargement are much less than are often claimed. At the same time, there are significant difficulties that have received very little attention in the public debate. The paper cites several downsides to enlargement, such as the threat of further manufacturing job losses; the redistribution of EU structural funds; the expansion of the EU bureaucratic machinery; and the imposition of page after page of EU regulations on the newly liberalised economies of the east. The paper concludes that overall, enlargement is a poor deal for Britain; a poor deal for the EU itself; and a poor deal for the new member states. This is not to say that enlargement is all bad news. There will undoubtedly be some sort of boost to trade (although rather less than is often suggested).