Rishi Sunak’s Rwanda bill: how much trouble is the prime minister really in as MPs threaten a parliamentary rebellion?

The legislative process in Britain consists of a series of discrete stages, each with its own purpose and function. A bill’s second reading is the discussion of, and vote on, the principle of the legislation. As Erskine May, the so-called bible of parliamentary procedure, puts it: “Its whole principle is at issue, and is affirmed or denied by the House.”

The last time a government lost a vote on the second reading of one of its own bills was 1986. The significance of that particular vote is not just that it took place almost 40 years ago, but that it was the only occasion a government with a working majority lost a bill at second reading in the entire 20th century. So, while we can say that it would not be unprecedented if the government went down to defeat over the Rwanda bill, it would be extremely unusual.

And while the defeat in 1986 was embarrassing, the shops bill, which attempted to liberalise Sunday trading laws, was not a central plank of the Thatcher government’s programme. The Rwanda vote is on something much more significant. Its defeat would leave a void where the government’s immigration policy was meant to be.

Is this a confidence vote?

Government figures have said they don’t see this vote as a matter of confidence, and there is nothing about losing a vote, or even a whole bill, that requires them to. Constitutionally, the government can lose this vote, keep calm and carry on, just as Margaret Thatcher did in 1986. Still, it’s fair to say that losing a measure of this significance would have been enough to bring down a government in the 19th century – and would still cause considerable political discomfort in the 21st.

The flip side of all of this, however, is that winning the vote – as still looks more likely – is not in itself something to be proud of. It is not a particularly remarkable achievement for a government with a majority of over 50 to win a second reading vote.

And even if it does win, celebrations should be muted as there are plenty of parliamentary hurdles ahead. After second reading, there will be a programme motion which sets out the timetable for the bill’s passage. These can be tricky. It was the programme motion that derailed House of Lords reform under the coalition government of 2010-15, for example. Then we have the committee and report stages – both opportunities for MPs to vote for amendments – before there is a third reading vote in the House of Commons on the bill as finally constituted.

Then it goes to the Lords, where the government does not have a majority and where multiple amendments are all but certain. In turn, the government can try to overturn Lords amendments with votes in the Commons, but each such vote is another hurdle and the chance for another rebellion, with no guarantee of success.

This is, at least in part, why MPs rarely vote down bills at their second reading – because they can always try to amend them later as they progress through parliament, to take out the worst bits or beef up the good bits. Better to focus on a rebellion where it might achieve something, they argue, rather than trying to kill a bill in its entirety.

Rebellion on both sides

Perhaps the key problem faced by the government whips is not the scale of the discontent per se, but that it comes from two opposing wings of the party.

Those on the right (crudely put) see the bill – in the words of the European Research Group – as “partial and incomplete”. They therefore want to see it strengthened. Other Conservative MPs (variously described as “moderate”, “mainstream” or “centrists” – you can pick your own nomenclature) think it already goes far enough, maybe even too far, and will resist any expansion of its powers. The problem for the whips is that any concessions granted to one group will make it more likely that the others will kick off.

In voting terms, these two groups have unequal opportunities. Because Labour has said it will oppose the bill -– and will almost certainly resist any of the amendments the right would desire – amendments from the right of the party will go down to defeat if they are opposed by the government, almost regardless of their size. On the other hand, it is plausible to imagine scenarios under which those on the left of the party might make common cause with the opposition and bring about government defeats.

Yet this isn’t quite the same as saying that the right are powerless. They have an important veto power. If, by the bill’s third reading, they are still unhappy, they can form an unholy alliance with the opposition and bring the whole measure down. Their plan, therefore, is to try to persuade the government to strengthen the bill by moving its own amendments, which they will support.

Yet this isn’t straightforward either. For one thing, the government has already said it cannot go much further. Plus, each one of these amendments is, in turn, a chance for the other wing of the party to rebel; and they too have a veto power at third reading. The last time a government lost a bill at third reading is 1977.

Incidentally, the phrase “partial and incomplete” comes from Corinthians in the Bible, from the verse that contains the famous line: “When I was a child, I spoke and thought and reasoned as a child. But when I grew up, I put away childish things.”

Maybe you think that apt, or maybe you don’t. But it also contains this sentence, which definitely sums up where we are: “Even the gift of prophecy reveals only part of the whole picture.”