article: Here is a selection of their comments: "I am disappointed that Martin McGuinness has chosen to take the position he has today. "His actions have meant that, at precisely the time we need our government to be active, we will have no government and no way to resolve the RHI problems. "It is clear that Sinn Féin's actions are not principled, they are political. "Let me make it clear, the DUP will always defend unionism and stand up for what is best for Northern Ireland and it appears from the deputy first minister's resignation letter that is what annoys Sinn Féin the most." "The UK government has a primary role to provide political stability in Northern Ireland and we'll be doing all we can over the coming days to work with the parties to find a solution to the current situation. "The position is very clear. If Sinn Féin does not nominate a replacement to the role of deputy first minister, then I'm obliged to call and election of the assembly within a reasonable period. "I would urge the leaders of the political parties to come together and work together to find a solution to current situation and we'll be doing all that we can with the political parties and the Irish government to that end." "A reasonable resolution could have been achieved which leads me to believe that this crisis goes beyond RHI and points to a more intractable situation. "The DUP and Sinn Féin's inability to work together is a fundamental flaw not envisaged in the Good Friday Agreement and will continue to burden the people of Northern Ireland as long as their best interests come second to entrenched party politics. "Today is a dark day for Northern Ireland. I am truly fearful for our future." "If this was just about RHI, Sinn Féin would hang in, they would hold the DUP and the first minister to account, they'd take steps to introduce cost controls and they'd support a public inquiry into what went wrong. "But this is not about RHI - it's about Sinn Féin. We've now had 10 years characterised by disappointment, debacles and scandals. "They are incapable of governing this country. They cannot see the greater good. The Ulster Unionists fought hard in 1998 to get these institutions up and running. We saw devolution as being for the benefit of the people. "I don't know what Sinn Féin and the DUP have in mind [following the resignation], but it's very clear they'll do what's good for the parties, not what's good for the electorate." "It looks like we're heading towards an election and that's happening because of Arele Foster's arrogance. "But if people want an election, let's have it, because people need to hear that we still have no programme for government and now we have costs spiralling out of control with RHI. "We also now won't have a public inquiry into all of this. We agree with Martin McGuinness when he tells us the DUP have disrespected the nationalist community. But some people wanted to stand
summary: Politicians, public bodies and the business community have been reacting to the news that Northern Ireland Deputy First Minister Martin McGuinness has resigned in protest at the handling of a botched heating scheme that is likely to cost the taxpayer £490m.