Voting on the European Union (Notification of Withdrawal) Bill 2016

Earlier this evening MPs voted on the European Union (Notification of Withdrawal) Bill 2016.

There were three divisions (all of which can be found at Digiminster):

• one division on an SNP amendment, which for all intents and purposes was the same as voting against the bill in toto;
• one division on the bill itself, and
• one division on the programme motion.

In this post I look at some of the patterns of voting on the second main division. In particular, I look at the effect of (a) MPs’ position before the referendum, which I have taken from this BBC page; and (b) opinion in MPs’ constituency, which I have estimated and described here and here.

First, the break-down by constituency:

• of the 220 MPs voting who represented a constituency which probably voted Remain, 103 (48%) voted in favour of the Bill
• of the 382 MPs voting who represented a constituency which probably voted Leave, 373 (98%) voted in favour of the Bill

As for the break-down by party,

• of the 214 Labour MPs voting, 167 (78%) voted in favour of the Bill
• of the 322 Conservative MPs voting, all but one (Ken Clarke) voted in favour of the Bill

Finally, the break-down by previous position:

• of the 154 MPs voting who had previously declared for Leave, all voted in favour of the Bill
• of the 443 MPs voting who had previously declared for Remain, 328 (74%) voted in favour of the Bill

In terms of the relationship between constituency opinion and the vote, there is a significant relationship between the estimated Leave percentage and the probability of voting in favour of the Bill. This is true both generally, and when we just analyse Labour MPs. This remains true when we control for MPs' positions before the referendum.

The graph shows MPs who voted for the second reading (top row) and MPs who voted against (bottom row). I have focused on the four main parties — the Conservative party, Labour, the Liberal Democrats and Scottish National Party. The further right the plotted point, the more strongly that MP's constituency voted Leave. The red dotted line indicates the trend for Labour.

Labour rebels (bottom row) are more likely to be found in pro-Remain constituencies

One way of re-stating the trend shown in the figure is to focus on the average Leave share of the vote in constituencies represented by those who voted in favour of or against the bill.

• The average Leave share of the vote where Labour MPs voted in favour was 56%
• The average Leave share of the vote where Labour MPs voted against was much lower, at 39%

If you are interested in the details of this analysis, I have put the data used up at Google Sheets. Please note that any claims about MPs' voting behaviour should be cross-checked against the original division lists at Digiminster, which may changes if and when errors in the lists come to light.

In the end, both the final result and the link between constituency opinion and voting behaviour seem to suggest that Parliament, by and large, had voting behaviour in the referendum very firmly in mind.