This post considers whether it is a convention of the British constitution that Parliament cannot direct the executive in the making of treaties. The context, of course, is the current tussle over whether the European Union (Withdrawal) Bill should be amended to allow the House of Commons a “meaningful vote” on the outcome of the current negotiations with the EU.
Amendments to this effect have been tabled by Viscount Hailsham and Dominic Grieve. These amendments stand out among the many, many amendments that have been debated in connection with the Withdrawal Bill. Government resistance to most amendments proposed by pro-European parliamentarians has been based on the proposition that Parliament cannot act against the “will of the people”, as (putatively) expressed in the June 2016 referendum. But in the case of the “meaningful vote” amendments, the Government is taking a different line. These amendments cannot be accepted (we are told) because they infringe the Crown’s historic prerogative of negotiating and concluding treaties. They must be defeated not (or not only) because they violate the “will of the people”, but because they violate monarchical authority.
Mr Jacob Rees-Mogg MP has based his opposition to a “meaningful vote” amendment on the principle of the separation of powers; he stated in this morning’s Times that the House of Commons “is not and cannot be an executive body”. Likewise, Mr David Davis stated in the debate on Tuesday, in relation to Dominic Grieve’s amendment:
What it amounts to is an unconstitutional shift that risks undermining our negotiations with the European Union. It enables Parliament to dictate to the Government their course of action in international negotiations.
Of course, as we know, the concept of unconstitutionality is a slippery one in this jurisdiction. In Madzimbamuto v Lardner-Burke and George  1 AC 645, a case which involved far-right nationalist politicians, the Privy Council famously stated:
It is often said that it would be unconstitutional for the United Kingdom Parliament to do certain things, meaning that the moral, political and other reasons against doing them are so strong that most people would regard it as highly improper if Parliament did these things. But that does not mean that it is beyond the power of Parliament to do such things. If Parliament chose to do any of them the courts could not hold the Act of Parliament invalid.
We must therefore interpret the position of Mr Davis, Mr Rees-Mogg and their supporters as being that a “meaningful vote” amendment would be unconstitutional not in the sense of being beyond the legal powers of Parliament to enact, but rather unconstitutional in the sense of being contrary to established understandings of the British constitution – contrary to convention, in other words.
It is trite law that the royal prerogative, as exercised in modern times by ministers, does indeed extend to negotiations such as those in which the Government is currently engaged with the European Union: “The conduct of foreign affairs, making treaties, making peace and war, conquering or annexing territories, are all aspects of the Royal prerogative” (Rahmatullah (No 2) v Ministry of Defence  UKSC 1, per Lady Hale). Presumably even members of the ERG would agree that only the first two of these things is relevant here. Yet I wish to suggest that one relatively recent precedent makes it clear that it is not contrary to British constitutional convention for the Commons to seek to direct the actions of the executive in the making of treaties.
The precedent comes from the time of the Treaty on European Union, better known as the Maastricht Treaty. After being negotiated by the Major Government, this treaty was implemented in UK law by means of the European Communities (Amendment) Act 1993. During the epic parliamentary battle over the legislation, the Government accepted a Labour amendment which in due course became Section 7 of the Act:
This Act shall come into force only when each House of Parliament has come to a Resolution on a motion tabled by a Minister of the Crown considering the question of adopting the Protocol on Social Policy.
While the wording of this section referred to a Government motion (“tabled by a Minister”), the intention was always that the Labour Opposition would table an amendment to the Government motion, and that that amendment would call upon the Government to adopt the Protocol on Social Policy. This was a part of the treaty – otherwise known as the Social Chapter – from which John Major had secured an opt-out for the UK on the grounds of economic policy.
The crucial votes were taken in the Commons on 22-23 July 1993. On 22 July, the Opposition narrowly failed to amend the Government’s motion, but it succeeded in voting down the motion itself. It will come as a surprise to no-one that the rebel Conservative MPs who voted with Labour on that occasion included certain current MPs who are opposed to a “meaningful vote” amendment (it would be invidious to mention the individuals concerned). Major responded by re-tabling the Government motion as a matter of confidence the following day. He won the resulting vote comfortably.
The key point is that Section 7 amounted to a deliberate and conscious attempt to empower Parliament to force the Government not to ratify an international treaty that it had negotiated unless it reconsidered its decision to reject certain terms of the treaty. It did not de jure allow the Commons to issue a legally binding direction to the Government as to what it ought to sign up to (and there was some suggestion at the time that the Government could ignore a Commons vote in favour of the Social Chapter – in Prime Minister’s questions on 20 July 1993, Major refused to be drawn on this point). But that is not the issue. The objections of Messrs Davis, Rees-Mogg et al. are based on broad constitutional principle – concern for the separation of powers – rather than on any narrow de jure point about the enforceability of a Commons resolution.
In conclusion, whatever the merits or otherwise of a “meaningful vote” amendment, such an amendment cannot be said to amount to an unprecedented departure from the conventional distribution of powers under the British constitution.
Francis Young is a Fellow of the Royal Historical Society, the author of 12 books, and holds a PhD from the University of Cambridge.
(Suggested citation: F. Young, ‘Parliament and Taking Back Control: A Precedent from the Maastricht Debates’, U.K. Const. L. Blog (15th Jun. 2018) (available at https://ukconstitutionallaw.org/)