evidence: Since Brexit - perhaps because of it - there has been a renewed debate on the merits of a united Ireland. [...] Michael Brennan, political editor of the Business Post, says: "Our polling has found that about 60% of people support a united Ireland. [...] And that's before we get to the - again disputed - roughly £10bn annual subvention to Northern Ireland from London and how much a united Ireland would cost taxpayers in the Republic.