What would be the question on the ballot paper?

The choice would have to be between leaving the EU on the agreed terms or staying. This could be awkward, as the terms might not be agreed by the time the decision to hold a referendum has to be taken. The deadline set by Michel Barnier, the EU negotiator, is October 2018. The outline of a deal might be clear by then and the terms of the deal would have to be sealed by the time of the vote, because they have to be approved by other member states.

The wording in 2016 was simple: “Should the UK remain a member of the EU or leave the EU?” It could be argued that simply to repeat it would bias the vote towards “leave” because it would imply that the answer people gave last time was the wrong one. On the other hand it might unbalance the question if the leave option included “... on the terms negotiated by HM Government?”