The referendum vote to leave the EU revealed deep social divides which cut across traditional party lines, and set up the most complex and divisive political reform agenda for decades. The manner in which the government proceeds with this agenda will depend very much on the patterns of electoral competition it faces. All governments are sensitive to electoral pressure, and the current government, with a perilously small and insecure support from the DUP, will be no exception. The electoral pressures on the government will be- in turn- to a large extent influenced by how the politics of immigration develop post-referendum, and how much immigration policy will change in the process of leaving the EU. This programme of high impact research will offer new insights on some of the most important new pressures on UK politics in the aftermath of the vote for Brexit.