West Lothian question
/ˌwɛst ˈləʊðɪən kwɛstʃ(ə)n/British Politics
noun
The British constitutional anomaly that, following devolution, Westminster MPs for Scottish and Welsh constituencies are unable to vote on Scottish or Welsh matters devolved, respectively, to the parliament and assembly of those countries, but are able to vote on equivalent matters concerning England, whilst MPs for English constituencies have no reciprocal influence on Scottish or Welsh matters; the problem or parliamentary question relating to this anomaly.
Origin
1970s. From West Lothian, the name of a former parliamentary constituency in Central Scotland (the MP for which, Thomas (Tam) Dalyell (b. 1932), raised this question in Parliament in debates on Scottish and Welsh devolution during 1977–8) + question.