In this research note, we propose studying a new trend of Europeanisation in national parliaments within the European Union (EU). We argue that further integration, combined with the opportunities and challenges presented by the Lisbon Treaty and the financial crisis, created pressure on national parliaments to expand the scrutiny process beyond European Affairs Committees. In this new phase of Europeanisation, parliaments are increasingly 'mainstreaming' EU affairs scrutiny, blurring the distinction between national and European policies and involving larger numbers of MPs. Following a review of existing research on the Europeanisation of national parliaments in the post-Lisbon era, we propose studying four dimensions of mainstreaming: the...