Temperature testing Brexit – the case of Northern Ireland

As the only regular polling of the views of Northern Ireland’s voters on Brexit, the Testing the Temperature polls (2021-2026) provide important insights into how opinions have evolved over time and in response to key developments. We provide here an analysis of the poll findings concerning attitudes towards the particular arrangements put in place by UK-EU agreement to manage the effects of Brexit on Northern Ireland, namely the Protocol on Ireland/Northern Ireland (since 2023, ‘the Windsor Framework’) and trust in those with responsibility for implementing it. This data reveals the degree to which existing political differences in Northern Ireland have been deepened post-Brexit, not only between political groupings but within them, specifically between hardline and more moderate unionists. Ultimately this study shows that opinion on Brexit-related matters is especially entrenched and slow to change in Northern Ireland, partly because it is a matter of principle for some and partly because the handling of Brexit has contributed to a decline in public confidence in political institutions and parties.