From the perspective of the default UK treaty-making process, the most important thing about today’s debate is that it is taking place at all.

Today’s debate takes place before formal negotiations on any of the four potential new trade deals have started. (The UK cannot formally open such talks until it has left the EU.)

The UK treaty-making process can be thought of as having four decision-making stages: the opening of negotiations; signature; legislation; and ratification.

In the default UK process, Parliament is only involved in the last two of these, legislation and ratification. If Parliament only gets involved in the process even immediately before a treaty is signed, the current Withdrawal Agreement impasse shows how difficult it can be, if parliamentarians have concerns, to amend a treaty at that stage.

Under the UK’s current constitutional and legislative framework, the government is able to open negotiations on a treaty without involving Parliament at all, using prerogative powers.

But the lesson from effective trade agreement processes elsewhere is that, for the UK’s ‘new’ trade agreements, the most important change needed to the default UK treaty-making process - at least with respect to Parliament - is to get the legislature involved at the outset.

From this perspective, today’s House of Commons debate is to be welcomed.

However, today’s debate also has a number of shortcomings.

For one thing, the government has moved to a debate on four specific potential trade agreement negotiations without setting out why these four have been selected, or where they might sit in any overall UK trade agreement strategy. Indeed, it is not clear whether the government proposes to publish any such detailed strategic document, setting out multi-year rationales, objectives and timelines for the negotiation of future UK trade deals.

Today’s debate is also a general debate: the government motion is a neutral one, MPs therefore cannot table or pass amendments, and the motion – assuming it is passed – will not be capable of expressing an explicit opinion of the House.

With respect to the four potential trade negotiations, the timing of the debate is also such as to raise questions about the value of, and reasons for, holding it today:

• Holding the debate on the Thursday of a week that was, until three weeks ago, due to be a recess week is unlikely to encourage wide interest and participation among MPs.

• The government has held public consultations on the four potential new trade agreements, which closed on 26 October 2018, but the results have not yet been published.

• Presumably partly as a consequence, ahead of today’s debate there is no published document from the government setting out its objectives or priorities for the four potential negotiations - no document of a draft ‘negotiating mandate’-type nature. This gravely limits the extent to which today’s debate can be well-informed, or an occasion for MPs to subject the government’s plans to effective scrutiny. Apart from anything else, there has been no document that the International Trade Committee or other select committees could examine or take evidence on, for example. But, in July 2018, International Trade Secretary Liam Fox said that before launching any formal trade agreement negotiation the government intended to publish an “‘Outline Approach’ to each negotiation”, setting out its “high-level objectives and scope”, and accompanied by a “scoping assessment”. With respect to the four negotiations now under discussion, it is not clear where today’s debate sits in relation to those intentions.

One important question that MPs should ask today is thus whether today’s debate is ‘it’, as far as the House of Commons is concerned, before the government opens negotiations with one or all of the UK’s new potential trade agreement partners. Or will there be a further occasion or occasions when MPs could debate, and perhaps express a view on, the government’s presumed decision to open negotiations, and its proposed negotiating objectives?

The timing of today’s debate also falls oddly in the context of the process-for-establishing-the-process for making ‘new’ UK trade agreements.

The possibility of holding a general debate early in the process of making a ‘new’ trade agreement was first raised by Liam Fox in his July 2018 statement. That statement remains the definitive statement so far of the government’s 'new' trade agreement-making plans.

In holding today’s debate, the government is thus proceeding in accordance with the Secretary of State’s July 2018 statement.

But parliamentarians in both Houses have criticised the July 2018 statement as inadequate; the process for making UK trade agreements is under live consideration in both Houses; and further steps on this front from the government are due imminently:

• Under an amendment moved successfully by the Labour opposition in the House of Lords on 21 January, that House will not take report stage of the Trade Bill “until Her Majesty’s Government has presented to both Houses proposals for a process for making international trade agreements … including roles for Parliament and the devolved legislatures and administrations in relation to both a negotiating mandate and a final agreement”. It is not clear whether the government proposals will come in the form of a statement and/or document, and/or amendments to the Trade Bill at report stage.

• In an ambitious report on trade policy transparency and scrutiny published at the end of December 2018, the House of Commons International Trade Committee recommended among other things that “Parliament should be given an opportunity to debate the Government’s Outline Approach on a substantive motion before the mandate is set and negotiations commence. … the Government should confirm that such a debate would be on an amendable, substantive motion”. The government’s response is due by the end of February.

• The House of Lords Constitution Committee is conducting an inquiry into parliamentary scrutiny of treaties, extending beyond trade agreements, with its report expected perhaps in March. Its report will feed into the inquiry into investigative and scrutiny committees in that House which is being carried out by the House of Lords Liaison Committee.

• The House of Commons Liaison Committee may also consider treaty- or trade agreement-making as part of its inquiry into the House of Commons select committee system, for which the deadline for written evidence is the end of February.

• The government is discussing with the devolved administrations potential future structures and processes for their involvement in future trade agreement-making, within the framework of the Joint Ministerial Committee architecture.

Further questions that MPs might usefully probe today are thus what further plans or proposals might be expected from the government, and when, if not today; and, specifically, whether the government will remain wedded to the general debate format on display today, or will be open to further enhancing Parliament’s role at this early stage in the trade agreement process, in light of committee recommendations.