For instance, if the unionist parties all fail to nominate a Deputy First Minster because they don't want to serve with a Sinn Fein First Minister, there is a simple solution which will prevent the collapse of devolution: Sinn Fein simply designates itself as a "unionist" party, which then requires the largest "nationalist" party, the SDLP to nominate a Deputy First Minister.  

If unionists refuse to contribute to the governance of Northern Ireland, nationalists may have to do it all by themselves.  

It may sound crazy, but it is not as far-fetched as it seems. By signing the GFA, Sinn Fein has recognised NI is part of the UK and it has operated the GFA institutions and the Executive under devolved powers granted by Westminster. Sinn Fein is therefore a de facto unionist party, even if its aspiration is to change that by way of a border poll as soon as possible.  

The prospect of a Sinn Fein First Minister and an SDLP Deputy First Minister should concentrate unionist minds wonderfully, and merely the threat of it should ensure the leading "unionist" party takes up the Deputy First Minister role. That party might even be Alliance, which is within the margin of error of becoming the largest "unionist" party in the most recent Lucidtalk poll.. It designated itself as Unionist in 2001 to prevent a collapse of the institutions then, so that precedent has been set.  

Longer term, party designations are a farce anyway, as formally non-aligned parties like Alliance and the Greens are deprived of the chance of the top jobs regardless of how well they do. The Good Friday Agreement should be encouraging the development of cross-community parties, rather than forcing them to become or remain part of the sectarian divide.  

With the non-aligned centre growing ever larger in NI, that is becoming an ever-larger anomaly and injustice. The time for a party like the DUP, with 17% of the projected vote, to hold everyone else to ransom has surely come to an end, and not before time.