ABSTRACT
For over a decade, enlargement and the prospect of enlargement dominated the European agenda in terms both of negotiations with aspirant neighbouring states and of securing the institutional reforms necessary to allow the European Union (EU) to function efficiently and effectively after a near doubling of its membership. As under Margaret Thatcher with the SEA, so changes promoted by the UK under Tony Blair would turn into problems contributing to the case put forward by those seeking to leave the EU. Almost soon as Tony Blair had been elected Prime Minister in 1997, the 1996/97 IGC culminated with the Treaty of Amsterdam. Breaking with convention, Tony Blair proposed to hold a referendum to ratify the Constitutional Treaty. Seen as rather a reluctant European during his time as Chancellor, Brown was in fact committed to the EU but he insisted on various 'red lines' before accepting what became known as the Lisbon Treaty.
