Legislative socialisation has long been an important force for politic
al deradicalisation in capitalist democracies worldwide. It remains ba
rely explored, however, in large part because it is a process very dif
ficult to track by conventional observational or survey methods, We ci
rcumvent these problems by taking advantage of an unusually propitious
vote on televising the proceedings of the British House of Commons to
chart the institutional deradicalisation of its Labour members. Socia
lisation effects are shown to be non-linear and, while the difference
is not statistically significant, to be marginally stronger among Memb
ers of Parliament (MPs) with frontbench experience. The somewhat great
er conservatism of frontbenchers, however, cannot be explained by anti
cipatory socialisation. Rather, it seems to be a function of doing wel
l under 'rules of the parliamentary game' threatened by proposals for
institutional reform.