MPs won’t find it easy to secure a confirmatory vote on a Brexit deal

With Parliament preparing to vote on the terms of the revised Brexit deal, there are reports that there could be a majority in the Commons in favour of a ‘confirmatory vote’. In other words, MPs could back Boris Johnson’s deal in return for the public being given a say.  

MPs will have a number of opportunities to push for a vote on a second referendum. Firstly, MPs can try to amend the meaningful vote motion if the government brings the deal to Parliament on Saturday. Secondly, the Liberal Democrats have already tabled an amendment to the Queen’s speech – this could be selected early next week. Finally, if both those attempts fail and the deal progresses, MPs will be able to table an amendment the Withdrawal Agreement Bill – which is required to put the Brexit deal into law.

The last timed MPs voted on the question of a confirmatory vote, it was rejected by 292-280 – with 66 abstentions. But even if supporters of a confirmatory vote are joined by around 40 of those abstainers, this would only be the first step towards securing a confirmatory vote. And, crucially, the backing of a majority in Parliament may not be enough.

A referendum requires primary legislation – which the rebels will struggle to pass by themselves

An amendment to a motion may indicate parliamentary support for a referendum, but primary legislation would be needed for a vote to happen. This would require the rebels to use their favoured tactic of taking control of the order paper in order to pass a bill.

However, there is a further complication. A referendum involves spending public money. This means any legislation to enable one will need parliamentary authorisation for that spending (known as a money resolution), which needs to be tabled by a minister. The government will be strongly opposed to a referendum, and is likely to refuse to bring forward such a motion.

What’s more, MPs were able to pass bills which required the government to extend Article 50 in a single day after significantly accelerating the legislative process. But referendum legislation is complex, and will need significant time for scrutiny – not least because the Electoral Commission has a statutory duty to test any proposed referendum question. This process would take a minimum of eight weeks and, so that there is an opportunity to amend the bill in line with the commission’s recommendation, it must be completed before the bill passes.

The government is likely to resist any attempts by MPs to compel it to bring forward legislation

Unable to legislate for a referendum without government support, MPs will need to explore what mechanisms they could use to persuade ministers to back their plan.

Passing a motion does not bind the government, and an amendment to the Queens’ speech would be easy for the government to ignore. However, an amendment to a meaningful vote motion could see MPs make their approval of the deal conditional on holding a referendum. Even then, however, the motion would have no legal force; and the current government has already shown a willingness to ignore the expressed will of Parliament.

A more watertight way to force the government to bring forward referendum legislation would be to require it to do so in law. The most obvious opportunity would be to amend the Withdrawal Agreement Bill. However, depending on the outcome of Saturday’s vote, this may be a risky strategy.

If the deal has been approved unconditionally then the terms of European Union (Withdrawal) (No. 2) Act mean the prime minister would no longer be obligated to extend Article 50. So MPs who pursue this strategy would have accept the risk that they could vote for the government's Brexit deal but then the government could simply drop the Withdrawal Agreement Bill entirely. This would mean the UK leaving the EU without a deal on 31 October.

This risk is reduced, or rather deferred, if the motion is amended – as per the Letwin amendment – to withhold official approval of the deal until implementing legislation is passed. This would require the prime minister to seek an extension.

Reaching agreement on the content of any referendum legislation will not be easy

Referendum legislation will need to specify a range of contentious details including the question, the franchise, any amendments to the regulatory framework, the detailed conduct rules for the poll and the date of the poll. Even if there is a majority for a referendum in principle, this might unravel once the details are under discussion.

The biggest scope for disagreement will be over the question—or the options to be put to a referendum. Several formats, with a range of options, have been proposed.

Labour’s preference is for a choice between a ‘credible leave option’ and remain. But if the government is responsible for introducing the legislation then it may put no deal – an option many MPs consider intolerable – on the ballot paper. If there aren’t the numbers in Parliament to amend this then MPs would face a difficult choice between supporting a vote in which no deal is an option and having no referendum at all.

The purpose of a referendum might be to present the public with a simple binary choice. However, the route to a referendum is anything but straightforward.