From the House of Lords European Union Committee:
The success or failure of the Government’s negotiation of the withdrawal from, and new relationship with, the EU will have profound and lasting implications for the United Kingdom. At stake are not only the economic prosperity of the nation, but our international standing and influence, our internal security, and the rights of the millions of EU citizens resident in the UK, and the more than one million UK citizens who live in EU Member States. The implications for the other 27 EU Member States, which have a shared interest in all these areas, are almost equally profound.
The Government’s renegotiation of the terms of the UK’s EU membership in late 2015 and early 2016, which led to the agreement of a ‘New Settlement’ by the European Council on 19 February 2016, was primarily an exercise of executive discretion, undertaken on the basis that the results would be put to the electorate. While we expressed a measure of disappointment at the level of engagement with Parliament in the course of the renegotiation, we understood the Government’s reluctance to offer a running commentary.
The forthcoming negotiations are both immeasurably more important and complex, and fundamentally different in nature. It is inconceivable that they should be conducted without effective parliamentary oversight. Indeed, in a parliamentary democracy we believe it is the right and duty of Parliament to ensure that the negotiations are scrutinised effectively at every stage.