The questions of wording

Opinion polls take up another constitutional role: this time in Scotland.

Alister Jack MP, the Secretary of State for Scotland in the UK government, said:

If you consistently saw 60 per cent of the population wanting a referendum — not wanting independence, but wanting a referendum — and that was sustained over a reasonably long period, then I would acknowledge that there was a desire for a referendum.

This will be the second time social research surveys will play a constitutional role. The Northern Ireland Act 1998 says a referendum will occur, in the view of the Secretary of State:

if at any time it appears likely to him that a majority of those voting would express a wish that Northern Ireland should cease to be part of the United Kingdom and form part of a united Ireland.

There are many ways to meet that condition. That includes repeated majorities in opinion polling. A “border poll” — a referendum on Irish reunification — decides Northern Ireland’s future.

Questions of wording and timing

Six in 10 respondents supporting an independence referendum seems a historic height. In six polls from 2007 to 2012, the internet panel company YouGov asked:

Do you support or oppose holding a referendum on Scottish independence?

The earliest two polls, in March and April 2007, had estimated support at 60% or…