These trends – the institutional strengthening of parliament and the waning size and coherence of the main parties – are not separate. Instead, they have arguably co-evolved. Parliamentary rules shape party behaviour, but parties also shape those rules, and recent changes in the party system have encouraged institutional reforms that may in turn have reinforced those changes.
Political developments in the last two decades have simultaneously undermined governments’ institutional and partisan tools for controlling parliament. This was obviously a large part of Theresa May’s difficulties – she led a minority government, and was dogged by frequent Conservative rebellions. Yet while these difficulties worsened with Brexit, they did not begin there. Brexit has clearly placed the British political system under considerable strain, but the government’s grip on parliament has been progressively weakening for several decades; Brexit has merely accelerated this process.
Radoslaw Zubek is Associate Professor of European Politics and Tutorial Fellow, Hertford College
Thomas Fleming is a DPhil Candidate in Politics