Brexit and Immigration: The Arc of the Pendulum

About the Author: Jonathan Thomas

Jonathan Thomas is a Senior Fellow at the Social Market Foundation think tank and has been the Migration Researcher there since 2018. He has published over 30 pieces on different aspects of the UK’s immigration and asylum regime, both pre and post Brexit, and has appeared before committees in both houses of parliament on immigration and asylum matters.

29th January 2026

A major new report from the Federal Trust and The Constitution Society tackles the role immigration policy played in causing Brexit, and that Brexit has since played in driving UK immigration policy.

In Brexit and Immigration: The Arc of the Pendulum, immigration researcher Jonathan Thomas tracks the arc of UK immigration policy and politics from the liberal 2000s to the restrictionist approaches to immigration seen today, considering the political and cultural forces behind this huge swing.

Notwithstanding the polarising nature of Brexit, immigration policy post-Brexit saw relative calm, the political consensus supporting a relatively liberal approach. But a doubling of immigration numbers compared with before Brexit, alongside the visible challenge to control posed by small boats crossing the Channel, saw public concern over immigration spiral back up, triggering a political reaction from the major parties.

The restrictiveness of today’s immigration policy proposals goes far beyond anything envisaged by Brexit. Some are even at odds with it. Yet Brexit can also be seen to have fuelled these developments, ‘take back control’ living on as an everlasting slogan for a quest for immigration control now pushing to greater extremes.

Politically, the UK’s huge pendulum swing on immigration policy has now delivered a mirror image of the more liberal immigration era of the 2000s. The pendulum may now be nearing the opposite extreme but, despite the recent fall in immigration numbers, Jonathan Thomas argues that:

“There are now so many and so much invested in the political battles around immigration that notwithstanding how far the pendulum has now travelled since Brexit, its momentum may mean it has further yet to go before moving back the other way.”

Read the Report here:

Read the Press Release here:

This report forms part of a series of major research reports the Federal Trust is publishing with the aim of analysing the impact of Brexit on the UK. The previous report in this series was published in June 2025 and is available here:

The Economic Impact of Brexit, Nine Years On: Was the Consensus Right?