From the British- Irish Parliamentary assembly meeting in Liverpool, as reported in the Sunday Times (£)

Both Protestants and Catholics in Northern Ireland who tend not to vote — in either Westminster or assembly elections — would reject a united Ireland in the event of a poll, according to research presented to Irish and British politicians.

“Non-voters” would be decisive in a border poll because they are likely to come out in record numbers, according to an analysis by Liverpool University’s Institute of Irish Studies (IIS).

Protestants who did not vote in the 2015 British general election expressed 86% support for staying in the UK, while 27.7% of Catholic non-voters also supported this, according to an IIS analysis.

“Sinn Fein is clearly calling for a border poll, but it brings to mind that old saying, ‘be careful what you wish for’,” said Peter Shirlow, director of the IIS, who presented the findings to the British Irish parliamentary assembly last week.

“[Non-voting] Protestants are quite clearly prepared to come out and vote in a period of what they would see as a significant reformation or change in society. The [Good Friday] agreement was obviously a major change in the governance of Northern Ireland, so they came out for that then disappeared again.”

The turnout for Northern Ireland’s referendum on the Good Friday agreement in 1998 was 81% — 16 points higher than the turnout for the 2017 elections to the Stormont assembly, and 25 points higher than the turnout in the 2011 and 2015 assembly elections.

Shirlow said the secretary of state for Northern Ireland was obliged to call a referendum on Irish unity if election results suggested that a majority could be in favour of such an outcome.

The IIS study found 56% of northern voters in 2015 favoured remaining in the UK and 34.6% wanted a united Ireland. While research suggested higher support for the Union among non-voters, the secretary could not legally consider those views.

It found that 30.7% of SDLP voters wanted to remain in the UK compared with 9.3% of Sinn Fein supporters, but 27.7% of Catholic non-voters also wanted to stay in the UK.