Parliament’s role in the Brexit process has been the subject of widespread controversy among politicians, commentators, and experts. This makes it important to understand exactly what kind of influence parliament wielded in that period. Tom Fleming and Lisa James shed new light on this question by summarising their recent article, Parliamentary Influence on Brexit Legislation, 2017-2019, as published in ‘Parliamentary Affairs’.

Parliament’s role in the Brexit process was – and remains – highly controversial. But despite this controversy, there is widespread agreement that parliament was unusually influential during this period, and particularly during the hung parliament that lasted from 2017 to 2019.

This verdict is largely based on parliament’s high-profile impact on the Brexit negotiations, where MPs famously torpedoed Theresa May’s exit deal, and delayed the UK’s eventual departure from the EU on multiple occasions. But parliament also considered a raft of important Brexit-related legislation, which aimed to unravel the UK’s membership of the EU and create new domestic regulatory frameworks. This legislation has been less studied, but is crucial to our understanding of the relationship between parliament and government in this period.

Our recent article therefore explored the extent and nature of parliament’s influence on this Brexit-related legislation. We did so by analysing the parliamentary passage of the 13 Brexit-related bills introduced in the 2017-19 parliament, including the fate of over 3000 proposed amendments.

More specifically, we explored three different mechanisms by which parliament can influence government legislation: passing non-government amendments; forcing government concessions; and influencing the government’s approach through ‘anticipated reactions’. For each mechanism, we investigated its prominence between 2017 and 2019, and compared this to evidence from earlier periods.