Deputy First Minister Martin McGuinness - a convicted IRA terrorist - resigned a week ago supposedly over a botched renewable heating scheme that is costing the taxpayer hundreds of millions. Under the terms of the Good Friday Agreement either the First Minister or Deputy First Minister's party can bring down the Northern Irish government simply by refusing to nominate a candidate for either post.
Sinn Féin won't have done this if they don't think they stand to gain. Reliable opinion polling is scarce in Northern Ireland so presumably they've got access to some private polling data that looks favourable.
|Convicted terrorist and IRA Council member turned politician, Martin McGuinness|