Ask Full Fact: what happens if parliament rejects a new EU deal?

“I can confirm today that the government will put the final deal that is agreed between the UK and the EU to a vote in both Houses of parliament before it comes into force.” Theresa May, 17 January 2017

The Prime Minister has announced that MPs and Lords will vote on a post-Brexit deal with the EU. A reader has asked us what happens if parliament says no.

Mrs May’s response when pressed on this was that “I'm sure that the British parliament will want to deliver on the views of the British people and respect the democratic decision that they've taken”.

We can add a little to this. There are several different scenarios, but if the government’s policy doesn’t change, then the UK would leave the EU no matter the outcome.

The ‘try again’ scenario

First, the government could go back to the EU and ask for an extension to the two-year negotiating period allowed under the Article 50 process for leaving. That’s possible if all 28 countries agree.

The ‘abort Brexit’ scenario

Second, the government could go back to the EU and ask whether we can just forget the whole thing and remain a member. That’s also possible if everyone agrees.

If there were objections—if the EU didn’t want to let the UK change its mind—it’s legally unclear whether we can do so anyway.

In this scenario, there would probably have to be a decision by the EU court on whether the UK can change its mind. A legal case is being taken to try to get the EU court’s answer on that as soon as possible.

The ‘no deal’ scenario

Third, the government could do nothing. The UK would then cease to be an EU member at the end of the two-year negotiating period, but with no deal.

That would create “legal limbo”: uncertainty on things like the status of EU migrants, the UK’s outstanding bills, and the regulations that businesses have to follow. MPs on the Brexit committee have described this as “unsatisfactory and potentially damaging to both sides”.

In terms of trade, the UK would fall back on World Trade Organisation (WTO) rules. While it has been argued that such rules would allow businesses to sell into the EU market on reasonable terms, an abrupt transition from single market membership to WTO terms could be disruptive.

A ‘second referendum’ scenario?

Fourth, it’s been suggested that there could be a referendum on the deal. We’ll leave the likelihood of that to the political pundits.

What we can say is that it would need to happen fairly quickly, as the clock would be ticking on the two-year Article 50 negotiation period. And unless we can change our minds about leaving, the choice for the electorate would only be between the deal on the table and the ‘no deal’ scenario.

Parliament was always going to be able to hold up the deal

A vote on “the final deal” is different to a vote on triggering the Article 50 process for leaving the EU in the first place. The Supreme Court case decided last month was about parliament having a vote at the outset, not at the end.

The government told the judges hearing that case that an Article 50 deal would be very likely to have to go before parliament for review before being ratified, under a law passed in 2010. But those procedures only allow parliament to delay international deals indefinitely, not shoot them down altogether.

Mrs May seems to have committed to giving MPs and Lords a yes or no vote on this one, outside those ordinary procedures. Such a vote "would not necessarily be legally binding, so the implications of a no vote are unclear", as the House of Commons Library puts it. Technically, the government could ignore a no vote and try to ratify the deal anyway.

But in terms of the legal mechanics, it still needs parliament to allow the treaty to pass under the 2010 act already mentioned, and to pass the laws necessary to implement it. In purely political terms, too, it doesn’t seem likely that the vote would simply be disregarded.

At least two deals could be voted on

It’s also worth thinking about what “final deal” we’re talking about, exactly. Because of the way Article 50 is worded, we and other analysts have always talked in terms of there being at least two major UK-EU deals after Brexit.

One is the ‘divorce deal’ on things like the status of UK citizens in other EU countries; EU budget liabilities; pending applications for EU funding and grants; and pending decisions of EU regulators.

These divorce issues, some of which are fairly narrow and technical, are what Article 50 is designed to cover. We have two years to negotiate this deal once Article 50 is triggered.

The other is a more forward-looking deal covering, among other things, trade. Whether or not this could be fully negotiated along with the divorce deal has been an open question. In part it depends on whether the EU wants to do that, whether it’s legally possible for it to do so, and what’s feasible within two years (or less). But the Prime Minister has repeatedly said that, for her part, that’s what she wants:

“I want us to have reached an agreement about our future partnership by the time the two-year Article 50 process has concluded.”

Such an agreement might not be fully fleshed out—it could more of a “framework”, leaving details to be filled in later.

So we’ve assumed that things go to plan and that parliament is presented with one treaty to ratify, covering both divorce and trade, within the two years specified by Article 50. It may well turn out differently, in which case we’ll revise this piece accordingly.